PIMCO Funds

Prospectus

DECEMBER 17, 2008

PIMCO EM Fundamental IndexPLUS^™ TR Strategy Fund

Share Class

P

PIMCO Funds Prospectus

PIMCO Funds

December 17, 2008

Share Class P

This prospectus describes the PIMCO EM Fundamental IndexPLUS^™ TR Strategy Fund (the “Fund”) offered by PIMCO Funds (the “Trust”). The Fund provides access to the professional investment advisory services offered by Pacific Investment Management Company LLC (“PIMCO”). As of September 30, 2008, PIMCO managed approximately $790 billion in assets. The firm’s institutional heritage is reflected in the PIMCO Fund offered in this prospectus.

The Fund offers Class P shares in this prospectus. This prospectus explains what you should know about the Fund before you invest. Please read it carefully.

The Securities and Exchange Commission has not approved or disapproved these securities, or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

1 PIMCO Funds

Table of Contents

Summary Information	3
Fund Summary	5
Summary of Principal Risks	7
Management of the Fund	10
Class P Shares	13
Purchases, Redemptions and Exchanges	14
How Fund Shares are Priced	22
Fund Distributions	23
Tax Consequences	24
Characteristics and Risks of Securities and Investment Techniques	24
Financial Highlights	36
Appendix A—Description of Securities Ratings	A-1

Prospectus 2

Summary Information

The table below describes certain investment characteristics of the Fund. Other important characteristics are described in the Fund Summary beginning on page 5. Following the table are certain key concepts which are used throughout the prospectus.

Category	Fund	Main Investments	Duration	Credit Quality(1)	Non-U.S. Dollar Denominated Securities
International Equity-Related	EM Fundamental IndexPLUS™ TR Strategy	Enhanced RAFI® Emerging Markets Fundamental Index® derivatives backed by a portfolio of fixed income instruments	Min. 1 year; max 2 years above the BCAG(2)	B to Aaa; max 10% of total assets below Baa	No Limitation

⁽¹⁾ As rated by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, determined by PIMCO to be of comparable quality.

⁽²⁾ The Barclays Capital U.S. Aggregate Index (“BCAG”) (formerly named the Lehman Brothers U.S. Aggregate Index) covers the U.S. investment grade fixed rate bond market, with index components for government and corporate securities, mortgage pass-through securities, and asset-backed securities.

Fixed Income Instruments “Fixed Income Instruments,” as used generally in this prospectus, includes:

• securities issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises (“U.S. Government Securities”);

• corporate debt securities of U.S. and non-U.S. issuers, including convertible securities and corporate commercial paper;

• mortgage-backed and other asset-backed securities;

• inflation-indexed bonds issued both by governments and corporations;

• structured notes, including hybrid or “indexed” securities and event-linked bonds;

• loan participations and assignments;

• delayed funding loans and revolving credit facilities;

• bank certificates of deposit, fixed time deposits and bankers’ acceptances;

• repurchase agreements on Fixed Income Instruments and reverse repurchase agreements on Fixed Income Instruments;

• debt securities issued by states or local governments and their agencies, authorities and other government-sponsored enterprises;

• obligations of non-U.S. governments or their subdivisions, agencies and government-sponsored enterprises; and

• obligations of international agencies or supranational entities.

Securities issued by U.S. Government agencies or government-sponsored enterprises may not be guaranteed by the U.S. Treasury.

The Fund may invest in derivatives based on Fixed Income Instruments.

Duration Duration is a measure of the expected life of a fixed income security that is used to determine the sensitivity of a security’s price to changes in interest rates. The longer a security’s duration, the more sensitive it will be to changes in interest rates. Similarly, a fund with a longer average portfolio duration will be more sensitive to changes in interest rates than a fund with a shorter average portfolio duration. By way of example, the price of a bond fund with an average duration of five years would be expected to fall approximately 5% if interest rates rose by one percentage point. Conversely, the price of a bond fund with an average duration of negative three years would be expected to rise approximately 3% if interest rates rose by one percentage point.

Credit Ratings In this prospectus, references are made to credit ratings of debt securities, which measure an issuer’s expected ability to pay principal and interest over time. Credit ratings are determined by rating organizations, such as Moody’s, S&P or Fitch. The following terms are generally used to describe the credit quality of debt securities depending on the security’s credit rating or, if unrated, credit quality as determined by PIMCO:

• high quality

• investment grade

• below investment grade (“high yield securities” or “junk bonds”)

For a further description of credit ratings, see “Appendix A—Description of Securities Ratings.” As noted in Appendix A, Moody’s, S&P and Fitch may modify their ratings of securities to show relative standing

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Summary Information (continued)

within a rating category, with the addition of numerical modifiers (1, 2 or 3) in the case of Moody’s, and with the addition of a plus (+) or minus (-) sign in the case of S&P and Fitch. The Fund may purchase a security, regardless of any rating modification, provided the security is rated at or above the Fund’s minimum rating category. For example, the Fund may purchase a security rated B3 by Moody’s, B- by S&P or B- by Fitch, because the Fund may purchase securities rated B.

Fund Descriptions, Performance, Fees and Disclosure of Portfolio Holdings The following summary identifies the Fund’s investment objective, principal investments and strategies, principal risks, performance information (once available) and fees and expenses. A more detailed “Summary of Principal Risks” describing principal risks of investing in the Fund begins after the Fund Summary. Investors should be aware that the investments made by the Fund and the results achieved by the Fund at any given time are not expected to be the same as those made by other mutual funds for which PIMCO acts as investment adviser, including mutual funds with names, investment objectives and policies similar to the Fund. Please see “Disclosure of Portfolio Holdings” in the Statement of Additional Information for information about the availability of the complete schedule of the Fund’s holdings.

It is possible to lose money on investments in the Fund.

An investment in the Fund is not a deposit of a bank and is not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Prospectus 4

PIMCO EM Fundamental IndexPLUS^™ TR Strategy Fund Ticker Symbols: N/A (P Class)

Principal Investments and Strategies Investment Objective Seeks total return which exceeds that of its benchmarks Fund Focus Enhanced RAFI^® Emerging Markets Fundamental Index derivatives backed by a portfolio of Fixed Income Instruments Average Collateral Fixed Income Duration See description below Credit Quality B to Aaa; maximum 10% of total assets below Baa Dividend Frequency Declared and distributed quarterly

The Fund seeks to exceed the total return of the FTSE RAFI^® Emerging Markets Index (the “Index”) and the MSCI Emerging Markets Index (the “Secondary Index”) by investing under normal circumstances in derivatives based on the Enhanced RAFI^® Emerging Markets Fundamental Index (“Enhanced RAFI EM”), an enhanced, performance recalibrated version of the Index, backed by a diversified short to intermediate duration portfolio comprised of Fixed Income Instruments, which may be represented by forwards or derivatives such as options, futures contracts, or swap agreements. The Index, the Secondary Index and Enhanced RAFI EM are further described below. The Fund may invest in common stocks, options, futures, options on futures and swaps, including derivatives based on the Index. The Fund is normally expected to primarily use Enhanced RAFI EM derivatives in place of Enhanced RAFI EM stocks to attempt to equal or exceed the performance of the Index and the Secondary Index. The values of Enhanced RAFI EM derivatives closely track changes in the value of Enhanced RAFI EM. However, Enhanced RAFI EM derivatives may be purchased with a fraction of the assets that would be needed to purchase the equity securities directly, so that the remainder of the assets may be invested in Fixed Income Instruments. Research Affiliates^®, LLC, the Fund’s sub-adviser, provides investment advisory services in connection with the Fund’s use of the Enhanced RAFI EM by, among other things, providing PIMCO, or counterparties designated by PIMCO, with a model portfolio reflecting the composition of Enhanced RAFI EM for purposes of developing Enhanced RAFI EM derivatives. PIMCO actively manages the Fixed Income Instruments held by the Fund with a view toward enhancing the Fund’s total return, subject to an overall portfolio duration which normally varies from a one year minimum duration to a maximum of two years above the duration of the Barclays Capital U.S. Aggregate Index (formerly named the Lehman Brothers U.S. Aggregate Index). As of September 30, 2008, the duration of the Barclays Capital U.S. Aggregate Index was 4.47 years. The Barclays Capital U.S. Aggregate Index covers the U.S. investment grade fixed rate bond market, with index components for government and corporate securities, mortgage pass-through securities, and asset-backed securities.

The Index consists of the largest constituent companies by fundamental accounting value which satisfy the Enhanced RAFI EM selection criteria. Unlike other indexes, which are frequently comprised of stocks weighted according to their market capitalization, the Index is weighted by a combination of fundamental factors, including sales, cash flow, book values and, if applicable, dividends (sales, cash flow and dividends are averaged over the prior five years). Indexes based on market capitalization such as the Secondary Index, generally overweight stocks which are overvalued, and underweight stocks which are undervalued. Indexes based on fundamental factors, however, such as the Index, seek to avoid this problem by weighting stocks based on variables that do not depend on the fluctuations of market valuation. Enhanced RAFI EM is a recalibrated version of the Index that may incorporate additional factors designed to improve performance and/or reduce volatility. Enhanced RAFI EM may include a broader array of stocks than the Index and may be further recalibrated to reflect price momentum in underlying stock prices. The Fund seeks to remain invested in Enhanced RAFI EM derivatives or Enhanced RAFI EM stocks even when Enhanced RAFI EM is declining. The Fund’s Secondary Index is a market capitalization weighted index that is designed to measure equity market performance of emerging markets.

The Fund typically will seek to gain exposure to Enhanced RAFI EM by investing in total return swap agreements. In a typical swap agreement, the Fund will receive the price appreciation (or depreciation) on Enhanced RAFI EM from the counterparty to the swap agreement in exchange for paying the counterparty an agreed upon fee. The Fund’s sub-adviser facilitates the Fund’s use of Enhanced

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PIMCO EM Fundamental IndexPLUS^™ TR Strategy Fund (continued)

RAFI EM derivatives by providing model portfolios of Enhanced RAFI EM securities to the Fund’s swap counterparties, so that the counterparties can provide total return swaps based on Enhanced RAFI EM to the Fund. Because Enhanced RAFI EM is a proprietary index, there may be a limited number of counterparties willing or able to serve as counterparties to a swap agreement. In addition to or instead of Enhanced RAFI EM swaps, the Fund may invest in other derivative instruments, “baskets” of stocks, individual securities, and exchange traded funds to maintain emerging markets equity exposure.

Assets not invested in equity securities or derivatives may be invested in Fixed Income Instruments. The Fund may invest up to 10% of its total assets in high yield securities (“junk bonds”) rated B or higher by Moody’s, or equivalently rated by S&P or Fitch, or, if unrated, determined by PIMCO to be of comparable quality. With respect to the Fund’s fixed income investments, the Fund may invest up to 15% of its total assets in securities and instruments that are economically tied to emerging market countries. With respect to the Fund’s fixed income investments, the Fund may invest, without limitation, in securities denominated in foreign currencies and in U.S. dollar denominated securities of foreign issuers. With respect to the Fund’s fixed income investments, the Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets. The Fund may also invest up to 10% of its total assets in preferred stocks.

Principal Risks Under certain conditions, generally in a market where the value of both Enhanced RAFI EM derivatives and Fixed Income Instruments are declining or in periods of heightened market volatility, the Fund may experience greater losses or lesser gains than would be the case if it invested directly in a portfolio of Enhanced RAFI EM stocks. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are:

•   Interest Rate Risk •   Credit Risk •   High Yield Risk •   Market Risk •   Issuer Risk •   Liquidity Risk •   Derivatives Risk •   Equity Risk •   Mortgage-Related and Other Asset-Backed Risk •   Foreign (Non-U.S.) Investment Risk •   Emerging Markets Risk •   Currency Risk •   Leveraging Risk •   Management Risk •   Short Sale Risk

Please see “Summary of Principal Risks” following the Fund Summary for a description of these and other risks of investing in the Fund.

Performance Information The Fund does not have a full calendar year of performance. Thus, no bar chart or Average Annual Total Returns table is included for the Fund.

Fees and Expenses of the Fund These tables describe the fees and expenses you may pay if you buy and hold Class P shares of the Fund:

Shareholder Fees (fees paid directly from your investment)

Redemption Fee⁽¹⁾ 2.00%

Annual Fund Operating Expenses (expenses that are deducted from Fund assets)

Share Class	Management Fees(2)	Distribution and/or Service (12b-1) Fees	Other Expenses(3)	Total Annual Fund Operating Expenses	Expense Reduction(4)	Net Annual Fund Operating Expenses
Class P	1.35%	None	0.01%	1.36%	(0.01)%	1.35%

⁽¹⁾ Shares that are held 7 days or less are subject to a redemption fee. The Trust may waive this fee under certain circumstances.

⁽²⁾ “Management Fees” reflect an advisory fee and a supervisory and administrative fee payable by the Fund to PIMCO. See “Management of the Fund—Management Fees” for additional information.

⁽³⁾ “Other Expenses” reflect estimated organizational expenses for the Fund’s first fiscal year.

⁽⁴⁾ PIMCO has contractually agreed, for the Fund’s current fiscal year (3/31), to waive its supervisory and administrative fee, or reimburse the Fund, to the extent that, due to organizational expenses and pro rata Trustees’ fees, the total annual fund operating expenses (excluding any expenses borne by the Fund not covered by the supervisory and administrative fee as described under “Management of the Fund—Management Fees” (other than organizational expenses and pro rata Trustees’ fees), if any) exceed 1.3549% of the Fund’s average net assets attributable to Class P shares. Under the Expense Limitation Agreement, which renews annually for a full fiscal year unless terminated by PIMCO upon at least 30 days’ notice prior to fiscal year-end, PIMCO may recoup these waivers and reimbursements in future periods, not exceeding three years, provided total expenses, including such recoupment, do not exceed the annual expense limit.

Examples.  The Examples are intended to help you compare the cost of investing in Class P shares of the Fund with the costs of investing in other mutual funds. The Examples assume that you invest $10,000 in the noted class of shares for the time periods indicated, and then redeem all your shares at the end of those periods. The Examples also assume that your investment has a 5% return each year, the reinvestment of all dividends and distributions, and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, the Examples show what your costs would be based on these assumptions.

Share Class	Year 1	Year 3
Class P	$137	$428

Prospectus 6

Summary of Principal Risks

The value of your investment in the Fund changes with the values of the Fund’s investments. Many factors can affect those values. The factors that are most likely to have a material effect on the Fund’s portfolio as a whole are called “principal risks.” The principal risks of the Fund are identified in the Fund Summary and are described in this section. The Fund may be subject to additional risks other than those described below because the types of investments made by the Fund can change over time. Securities and investment techniques mentioned in this summary that appear in bold type are described in greater detail under “Characteristics and Risks of Securities and Investment Techniques.” That section and “Investment Objectives and Policies” in the Statement of Additional Information also include more information about the Fund, its investments and the related risks. There is no guarantee that the Fund will be able to achieve its investment objective. It is possible to lose money by investing in the Fund.

Interest Rate Risk Interest rate risk is the risk that fixed income securities will decline in value because of changes in interest rates. As nominal interest rates rise, the value of certain fixed income securities held by the Fund is likely to decrease. A nominal interest rate can be described as the sum of a real interest rate and an expected inflation rate. Fixed income securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than securities with shorter durations. Inflation-indexed bonds, including Treasury Inflation-Protected Securities, decline in value when real interest rates rise. In certain interest rate environments, such as when real interest rates are rising faster than nominal interest rates, inflation-indexed bonds may experience greater losses than other fixed income securities with similar durations.

Variable and floating rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, floating rate securities will not generally increase in value if interest rates decline. Inverse floating rate securities may decrease in value if interest rates increase. Inverse floating rate securities may also exhibit greater price volatility than a fixed rate obligation with similar credit quality. When the Fund holds variable or floating rate securities, a decrease (or, in the case of inverse floating rate securities, an increase) in market interest rates will adversely affect the income received from such securities and the net asset value of the Fund’s shares.

Credit Risk The Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to a derivatives contract, repurchase agreement or a loan of portfolio securities, is unable or unwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. Securities are subject to varying degrees of credit risk, which are often reflected in credit ratings. Municipal Bonds are subject to the risk that litigation, legislation or other political events, local business or economic conditions, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest.

High Yield Risk Funds that invest in high yield securities and unrated securities of similar credit quality (commonly known as “junk bonds”) may be subject to greater levels of credit and liquidity risk than funds that do not invest in such securities. These securities are considered predominately speculative with respect to the issuer’s continuing ability to make principal and interest payments. An economic downturn or period of rising interest rates could adversely affect the market for these securities and reduce the Fund’s ability to sell these securities (liquidity risk). If the issuer of a security is in default with respect to interest or principal payments, the Fund may lose its entire investment.

Market Risk The market price of securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. Securities may decline in value due to factors affecting securities markets generally or particular industries

7 PIMCO Funds

represented in the securities markets. The value of a security may decline due to general market conditions which are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors which affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Equity securities generally have greater price volatility than fixed income securities.

Issuer Risk The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services.

Liquidity Risk Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund’s investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and the difficulty in purchasing and selling such securities or instruments, may be unable to achieve its desired level of exposure to a certain sector. To the extent that the Fund’s principal investment strategies involve foreign (non-U.S.) securities , derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to liquidity risk.

Derivatives Risk Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The various derivative instruments that the Fund may use are referenced under “Characteristics and Risks of Securities and Investment Techniques—Derivatives” in this prospectus and described in more detail under “Investment Objectives and Policies” in the Statement of Additional Information. The Fund typically uses derivatives as a substitute for taking a position in the underlying asset and/or as part of a strategy designed to reduce exposure to other risks, such as interest rate or currency risk. The Fund may also use derivatives for leverage, in which case their use would involve leveraging risk. The Fund’s use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this section, such as liquidity risk, interest rate risk, market risk, credit risk and management risk. They also involve the risk of mispricing or improper valuation and the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset, rate or index. If the Fund invests in a derivative instrument, it could lose more than the principal amount invested. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial.

Equity Risk The values of equity securities, such as common stocks and preferred stocks, may decline due to general market conditions which are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors which affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities.

Mortgage-Related and Other Asset-Backed Risk Mortgage-related andother asset-backed securities are subject to certain additional risks. Generally, rising interest rates tend to extend the duration of fixed rate mortgage-related securities, making them more sensitive to changes in interest rates. As a result, in a period of rising interest rates, if the Fund holds mortgage-related securities, it may exhibit additional volatility. This is known as extension risk. In addition, adjustable and fixed

Prospectus 8

rate mortgage-related securities are subject to prepayment risk. When interest rates decline, borrowers may pay off their mortgages sooner than expected. This can reduce the returns of the Fund because the Fund may have to reinvest that money at the lower prevailing interest rates. The Fund’s investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

Foreign (Non-U.S.) Investment Risk When the Fund invests in foreign (non-U.S.) securities, it may experience more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies. The securities markets of many foreign countries are relatively small, with a limited number of companies representing a small number of industries. Additionally, issuers of foreign securities are usually not subject to the same degree of regulation as U.S. issuers. Reporting, accounting and auditing standards of foreign countries differ, in some cases significantly, from U.S. standards. Also, nationalization, expropriation or confiscatory taxation, currency blockage, political changes or diplomatic developments could adversely affect the Fund’s investments in a foreign country. In the event of nationalization, expropriation or other confiscation, the Fund could lose its entire investment in foreign securities. Adverse conditions in a certain region can adversely affect securities of other countries whose economies appear to be unrelated. To the extent that the Fund invests a significant portion of its assets in a specific geographic region like Eastern Europe or Asia, the Fund will generally have more exposure to regional economic risks associated with foreign investments.

Emerging Markets Risk Foreign investment risk may be particularly high to the extent that the Fund invests in emerging market securities that are economically tied to countries with developing economies. These securities may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign countries.

Currency Risk If the Fund invests directly in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, foreign (non-U.S.) currencies, or in derivatives that provide exposure to foreign (non-U.S.) currencies, it will be subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged.

Currency rates in foreign countries may fluctuate significantly over short periods of time for a number of reasons, including changes in interest rates, intervention (or the failure to intervene) by U.S. or foreign governments, central banks or supranational entities such as the International Monetary Fund, or by the imposition of currency controls or other political developments in the United States or abroad. As a result, the Fund’s investments in foreign currency-denominated securities may reduce the returns of the Fund.

Leveraging Risk Certain transactions may give rise to a form of leverage. Such transactions may include, among others, reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions. The use of derivatives may also create leveraging risk. To mitigate leveraging risk, PIMCO will segregate or “earmark” liquid assets or otherwise cover transactions that may give rise to such risk. The Fund also may be exposed to leveraging risk by borrowing money for investment purposes. Leveraging may cause the Fund to liquidate portfolio positions to satisfy its obligations or to meet segregation requirements when it may not be advantageous to do so. Leveraging, including borrowing, may cause the Fund to be more volatile than if the Fund had not been leveraged. This is because leveraging tends to exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities.

Management Risk The Fund is subject to management risk because it is an actively managed investment portfolio. PIMCO and the individual portfolio manager will apply investment techniques and risk analysis in making investment decisions for the Fund, but there can be no guarantee that these decisions will produce the desired results. Additionally,

9 PIMCO Funds

legislative, regulatory, or tax developments may affect the investment techniques available to PIMCO and the portfolio manager in connection with managing the Fund and may also adversely affect the ability of the Fund to achieve its investment objective. Because the Fund invests in derivatives that are linked to Enhanced RAFI EM, it will be subject to the risks associated with the management of Enhanced RAFI EM by the sub-adviser to the Fund.

Short Sale Risk The Fund’s short sales, if any, are subject to special risks. A short sale involves the sale by the Fund of a security that it does not own with the hope of purchasing the same security at a later date at a lower price. The Fund may also enter into a short derivative position through a futures contract or swap agreement. If the price of the security or derivative has increased during this time, then the Fund will incur a loss equal to the increase in price from the time that the short sale was entered into plus any premiums and interest paid to the third party. Therefore, short sales involve the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. Also, there is the risk that the third party to the short sale may fail to honor its contract terms, causing a loss to the Fund.

Management of the Fund

Investment Adviser and Administrator PIMCO serves as the investment adviser and the administrator (serving in its capacity as administrator, the “Administrator”) for the Fund. Subject to the supervision of the Board of Trustees, PIMCO is responsible for managing the investment activities of the Fund and the Fund’s business affairs and other administrative matters.

PIMCO is located at 840 Newport Center Drive, Newport Beach, CA 92660. Organized in 1971, PIMCO provides investment management and advisory services to private accounts of institutional and individual clients and to mutual funds. As of September 30, 2008, PIMCO had approximately $790 billion in assets under management.

PIMCO has engaged Research Affiliates, LLC, a California limited liability company (“Research Affiliates”), to serve as the sub-adviser to the Fund. Research Affiliates is located at 155 North Lake Avenue, Suite 900, Pasadena, CA 91101.

Management Fees The Fund pays for the advisory and supervisory and administrative services it requires under what is essentially an all-in fee structure. The Management Fees shown in the Annual Fund Operating Expenses table reflect both an advisory fee and a supervisory and administrative fee.

•    Advisory Fee.  The Fund pays PIMCO fees in return for providing investment advisory services. The Fund will pay monthly advisory fees to PIMCO at the annual rate (stated as a percentage of the average daily net assets of the Fund) of 0.85%.

In addition, PIMCO will pay a fee to Research Affiliates at the annual rate of 0.12% of the average daily net assets of the Fund.

A discussion of the basis for the Board of Trustees’ approval of the Fund’s investment advisory contract and sub-advisory agreement will be available in the Fund’s Annual Report to shareholders for the fiscal year ended March 31, 2009.

•    Supervisory and Administrative Fee.  The Fund pays for the supervisory and administrative services it requires under what is essentially an all-in fee structure. Class P shareholders of the Fund pay a supervisory and administrative fee to PIMCO, computed as a percentage of the Fund’s assets attributable in the aggregate to that

Prospectus 10

class of shares. PIMCO, in turn, provides or procures supervisory and administrative services for Class P shareholders and also bears the costs of various third-party services required by the Fund, including audit, custodial, portfolio accounting, legal, transfer agency and printing costs. The Fund does bear other expenses which are not covered under the supervisory and administrative fee which may vary and affect the total level of expenses paid by Class P shareholders, such as taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, extraordinary expenses (such as litigation and indemnification expenses) and fees and expenses of the Trust’s Independent Trustees and their counsel. PIMCO generally earns a profit on the supervisory and administrative fee paid by the Fund. Also, under the terms of the supervision and administration agreement, PIMCO, and not Fund shareholders, would benefit from any price decreases in third-party services, including decreases resulting from an increase in net assets.

The Fund will pay PIMCO monthly supervisory and administrative fees at the annual rate (stated as a percentage of the average daily net assets attributable in the aggregate to the Fund’s Class P shares) of 0.50%.

PIMCO and/or its affiliates may make payments to selected brokers and other financial intermediaries (“service agents”) for providing administrative, sub-transfer agency, sub-accounting and other shareholder services to shareholders holding Class P shares in nominee or street name, including, without limitation, the following services: receiving, aggregating and processing purchase, redemption and exchange orders at the service agent level; providing and maintaining elective services with respect to Class P shares such as check writing and wire transfer services; providing and maintaining pre-authorized investment plans; communicating periodically with shareholders; acting as the sole shareholder of record and nominee for holders of Class P shares; maintaining account records for shareholders; answering questions and handling correspondence from shareholders about their accounts; issuing confirmations for transactions by shareholders; collecting and posting distributions to shareholder accounts; capturing and processing tax data; processing and mailing trade confirmations, monthly statements, prospectuses, shareholder reports and other SEC-required communications; and performing similar account administrative services. The actual services provided, and the payments made for such services, vary from firm to firm. PIMCO currently estimates that it and/or its affiliates will pay up to 0.10% per annum of the value of assets in the relevant accounts out of PIMCO’s and/or its affiliates’ resources, including the Class P supervisory and administrative fees paid under the Trust’s supervision and administration agreement, to service agents for providing the services described above. Payments described above may be material to service agents relative to other compensation paid by the Fund and/or PIMCO and/or its affiliates and may be in addition to other fees, such as the revenue sharing or “shelf space” fees paid to such service agents. The payments described above may differ depending on the Fund and may vary from amounts paid to the Trust’s transfer agent for providing similar services to other accounts.

PIMCO has contractually agreed, for the Fund’s current fiscal year, to reduce total annual fund operating expenses for Class P shares, by waiving a portion of its supervisory and administrative fee or reimbursing the Fund, to the extent that they would exceed, due to the payment of organizational expenses and pro rata Trustees’ fees, the sum of the Fund’s advisory fee and supervisory and administrative fee and other expenses borne by the Fund not covered by the supervisory and administrative fee as described above (other than organizational expenses and pro rata Trustees’ fees), plus 0.49 basis points. PIMCO may recoup these waivers and reimbursements for a period not exceeding three years, provided that total expenses, including such recoupment, do not exceed the annual expense limit.

11 PIMCO Funds

Individual Portfolio Manager The following individual has primary responsibility for managing the Fund.

Portfolio Manager	Since		Recent Professional Experience
William H. Gross	12/08	*	Managing Director, Co-Chief Investment Officer and a founding partner of PIMCO. Mr. Gross has been associated with PIMCO since 1971.
*    Since inception of the Fund.

Please see the Statement of Additional Information for additional information about other accounts managed by the portfolio manager, the portfolio manager’s compensation and the portfolio manager’s ownership of shares of the Fund.

Distributor The Trust’s Distributor is Allianz Global Investors Distributors LLC (“AGID” or “Distributor”), an indirect subsidiary of Allianz Global Investors of America L.P. (“AGI”), PIMCO’s parent company. The Distributor, located at 1345 Avenue of the Americas, New York, NY 10105, is a broker-dealer registered with the Securities and Exchange Commission (“SEC”).

Regulatory and Litigation Matters Since February 2004, PIMCO, AGI, AGID, and certain of their affiliates, including the Trust, Allianz Funds (formerly known as PIMCO Funds: Multi-Manager Series) (a complex of mutual funds managed by affiliates of PIMCO), certain Trustees of the Trust, and certain employees of PIMCO have been named as defendants in eleven lawsuits filed in various jurisdictions. These lawsuits concern “market timing,” and they have been transferred to and consolidated for pre-trial proceedings in a multi-district litigation proceeding in the U.S. District Court for the District of Maryland. The lawsuits have been commenced as putative class actions on behalf of investors who purchased, held or redeemed shares of the various series of the Trust and the Allianz Funds during specified periods, or as derivative actions on behalf of the Trust and Allianz Funds. These lawsuits seek, among other things, unspecified compensatory damages plus interest and, in some cases, punitive damages, the rescission of investment advisory contracts, the return of fees paid under those contracts and restitution.

These actions generally allege that certain hedge funds were allowed to engage in “market timing” in certain funds of the Trust and Allianz Funds and this alleged activity was not disclosed. Pursuant to tolling agreements dated January 14, 2005 entered into with the derivative and class action plaintiffs, PIMCO, certain Trustees of the Trust, and certain employees of PIMCO who were previously named as defendants have all been removed as defendants in the market timing actions; however, the plaintiffs continue to assert claims on behalf of the shareholders of the Trust or on behalf of the Trust itself against other defendants. By order dated November 3, 2005, the U.S. District Court for the District of Maryland granted the Trust’s motion to dismiss claims asserted against it in a consolidated amended complaint where the Trust was named, in the complaint, as a nominal defendant. Thus, at present the Trust is not a party to any “market timing” lawsuit.

Two nearly identical class action civil complaints have been filed in August 2005, in the Northern District of Illinois Eastern Division, alleging that the plaintiffs each purchased and sold a 10-year Treasury note futures contract and suffered damages from an alleged shortage when PIMCO held both physical and futures positions in 10-year Treasury notes for its client accounts. The two actions have been consolidated into one action, and the two separate complaints have been replaced by a consolidated complaint. PIMCO is a named defendant, and the Trust has been added as a defendant, to the consolidated action. PIMCO and the Trust strongly believe the complaint is without merit and intend to vigorously defend themselves.

In April 2006, certain funds of the Trust and certain other funds managed by PIMCO were served in an adversary proceeding brought by the Official Committee of Asbestos Claimants of G-I Holdings, Inc. in G-I Holdings, Inc.’s bankruptcy in the District of New Jersey. In July 2004, PIMCO was named in this lawsuit and remains a defendant. The plaintiff seeks to recover for the bankruptcy estate assets that were transferred by the predecessor entity of G-I Holdings, Inc. to a wholly-owned subsidiary in 1994. The subsidiary has since issued

Prospectus 12

notes, of which certain funds of the Trust and certain other funds managed by PIMCO are alleged to be holders. The complaint alleges that in 2000, more than two hundred noteholders—including certain funds of the Trust and certain other funds managed by PIMCO—were granted a second priority lien on the assets of the subsidiary in exchange for their consent to a refinancing transaction and the granting of a first priority lien to the lending banks. The plaintiff is seeking invalidation of the lien in favor of the noteholders and/or the value of the lien. On June 21, 2006, the District of New Jersey overturned the Bankruptcy Court’s decision granting permission to file the adversary proceeding and remanded the matter to the Bankruptcy Court for further proceedings. Following a motion to reconsider, the District Court upheld its remand on August 7, 2006, and instructed the Bankruptcy Court to conduct a “cost-benefit” analysis of the Committee’s claims, including the claims against the noteholders. Currently, the Bankruptcy Court has stayed the adversary proceeding while it considers a Plan of Reorganization. If the Plan of Reorganization is approved, it is expected that the adversary proceeding will be dismissed. It is not known at this time when the Plan of Reorganization may be approved, if at all. This matter is not expected to have a material adverse effect on either the relevant registered investment companies and other funds or PIMCO.

It is possible that these matters and/or other developments resulting from these matters could result in increased fund redemptions or other adverse consequences to the Fund. However, PIMCO and AGID believe that these matters are not likely to have a material adverse effect on the Fund or on PIMCO’s or AGID’s ability to perform their respective investment advisory or distribution services relating to the Fund.

The foregoing speaks only as of the date of this prospectus. While there may be additional litigation or regulatory developments in connection with the matters discussed above, the foregoing disclosure of litigation and regulatory matters will be updated only if those developments are material.

Class P Shares

The Trust offers investors Class P shares of the Fund in this Prospectus.

With the exception of the fees charged in connection with sales (redemptions) or exchanges of Class P shares of the Fund within a certain number of days after acquisition (“redemption fees”), the Fund does not charge any sales charges (loads) or other fees in connection with purchases, redemptions or exchanges of Class P shares.

•    Arrangements with Service Agents.  Class P shares of the Fund may be offered through certain brokers and other financial intermediaries (“service agents”) that have established a shareholder servicing relationship with respect to the Trust on behalf of their customers. Service agents may impose additional or different conditions than the Trust on purchases, redemptions or exchanges of Fund shares by their customers. Service agents may also independently establish and charge their customers transaction fees, account fees and other amounts in connection with purchases, sales and redemptions of Fund shares in addition to any fees charged by the Trust. These additional fees may vary over time and would increase the cost of the customer’s investment and lower investment returns. Each service agent is responsible for transmitting to its customers a schedule of any such fees and information regarding any additional or different conditions regarding purchases, redemptions and exchanges. Shareholders who are customers of service agents should consult their service agents for information regarding these fees and conditions. Among the service agents with whom the Trust may enter into a shareholder servicing relationship are firms whose business involves or includes investment consulting, or whose parent or affiliated companies are in the investment consulting business, that may recommend that their clients utilize PIMCO’s investment advisory services or invest in the Fund or in other products sponsored by PIMCO and its affiliates.

13 PIMCO Funds

In addition, PIMCO and/or its affiliates may make payments to service agents for providing certain services with respect to Class P shares of the Fund held through such service agents, out of their own resources including supervisory and administrative fees received from the Fund. Additional information about these payments, including the expected amounts thereof, together with a description of the services for which they are made, is included under “Management of the Fund—Supervisory and Administrative Fee”. The actual services provided, and the payments made for such services, may vary from firm to firm. These amounts would be in addition to amounts paid to the Trust’s transfer agents or other services providers. PIMCO and its affiliates do not audit the service agents to determine whether they are providing the services for which they are receiving such payments. Although the payments described above are not intended to compensate the service agents for marketing the Fund, they may provide an additional incentive to service agents to actively promote the Fund and, depending on the arrangements a service agent may have in place with other mutual funds or their sponsors at any particular time, a service agent may have a financial incentive to promote the Fund (or share class of the Fund) over other mutual fund options (or other funds or share classes of the Fund) available.

•    Payments by PIMCO.  From time to time, PIMCO may pay or reimburse broker-dealers, banks, recordkeepers or other financial institutions for PIMCO’s attendance at investment forums sponsored by such firms, or PIMCO may co-sponsor such investment forums with such financial institutions. Payments and reimbursements for such activities are made out of PIMCO’s own assets and at no cost to the Fund. These payments and reimbursements may be made from profits received by PIMCO from advisory fees and supervisory and administrative fees paid to PIMCO by the Fund. Such activities by PIMCO may provide incentives to financial institutions to sell shares of the Fund. Additionally, these activities may give PIMCO additional access to sales representatives of such financial institutions, which may increase sales of Fund shares.

From time to time, PIMCO or its affiliates may pay investment consultants or their parent or affiliated companies for certain services including technology, operations, tax, or audit consulting services, and may pay such firms for PIMCO’s attendance at investment forums sponsored by such firms or for various studies, surveys, or access to databases. Subject to applicable law, PIMCO and its affiliates may also provide investment advisory services to investment consultants and their affiliates and may execute brokerage transactions on behalf of the Fund with such investment consultants or their affiliates. These consultants or their affiliates may, in the ordinary course of their investment consultant business, recommend that their clients utilize PIMCO’s investment advisory services or invest in the Fund or in other products sponsored by PIMCO and its affiliates.

Purchases, Redemptions and Exchanges

Purchasing Shares Investors may purchase Class P shares of the Fund at the relevant net asset value (“NAV”) of that class without a sales charge.

Class P shares are offered through certain asset allocation, wrap fee and other similar programs offered by broker-dealers and other intermediaries. Broker-dealers, other intermediaries, pension and profit-sharing plans, employee benefit trusts and employee benefit plan alliances also may purchase Class P shares. These entities may purchase Class P shares only if the plan or program for which the shares are being acquired will not require the Fund to pay any type of administrative payment per participant account to any third party.

•    Investment Minimums.  The minimum initial investment for Class P shares is $5 million, except that the minimum initial investment may be modified for certain financial intermediaries that submit trades on behalf of underlying investors. In addition, the minimum initial investment may be modified for certain employees of PIMCO and its affiliates.

Prospectus 14

The Trust or the Distributor may waive the minimum initial investment for other categories of investors at its discretion.

•    Timing of Purchase Orders and Share Price Calculations.  A purchase order received by the Trust or its designee prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m., Eastern time), on a day the Trust is open for business, together with payment made in one of the ways described below, will be effected at that day’s NAV. An order received after the close of regular trading on the NYSE will be effected at the NAV determined on the next business day. However, orders received by certain retirement plans, broker-dealers and other financial intermediaries on a business day prior to the close of regular trading on the NYSE and communicated to the Trust or its designee prior to such time as agreed upon by the Trust and intermediary, on the following business day will be effected at the NAV determined on the prior business day. The Trust is “open for business” on each day the NYSE is open for trading, which excludes the following holidays: New Year’s Day, Martin Luther King, Jr. Day, Presidents’ Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day. Purchase orders will be accepted only on days on which the Trust is open for business.

•    Initial Investment.  Investors may open an account by completing and signing a Client Registration Application and mailing it to PIMCO Funds, c/o BFDS Midwest, 330 W. 9th Street, Kansas City, MO 64105. A Client Registration Application may be obtained by calling 1-800-927-4648.

Except as described below, an investor may purchase Class P shares only by wiring federal funds to the Trust’s transfer agent, Boston Financial Data Services—Midwest (“Transfer Agent”), 330 West 9th Street, Kansas City, MO 64105. Before wiring federal funds, the investor must telephone the Trust at 1-800-927-4648 to receive instructions for wire transfer and must provide the following information: name of authorized person, shareholder name, shareholder account number, name of Fund and share class, and amount being wired.

An investor may purchase shares without first wiring federal funds if the proceeds of the investment are derived from an investment by broker-dealers, institutional clients or other financial intermediaries which have established a shareholder servicing relationship with the Trust on behalf of their customers.

•    Additional Investments.  An investor may purchase additional Class P shares of the Fund at any time by calling the Trust and wiring federal funds to the Transfer Agent as outlined above.

•    Verification of Identity.  To help the federal government combat the funding of terrorism and money laundering activities, federal law requires all financial institutions to obtain, verify and record information that identifies each person that opens a new account, and to determine whether such person’s name appears on government lists of known or suspected terrorists and terrorist organizations. As a result, the Fund must obtain the following information for each person that opens a new account:

1.  Name;

2.  Date of birth (for individuals);

3.  Residential or business street address; and

4.  Social security number, taxpayer identification number, or other identifying number.

Federal law prohibits the Fund and other financial institutions from opening a new account unless they receive the minimum identifying information listed above.

Individuals may also be asked for a copy of their driver’s license, passport or other identifying document in order to verify their identity. In addition, it may be necessary to verify an individual’s identity by

15 PIMCO Funds

cross-referencing the identification information with a consumer report or other electronic database. Additional information may be required to open accounts for corporations and other entities.

After an account is opened, the Fund may restrict your ability to purchase additional shares until your identity is verified. The Fund also may close your account and redeem your shares or take other appropriate action if it is unable to verify your identity within a reasonable time.

•     Other Purchase Information.  Purchases of the Fund’s Class P shares will be made in full and fractional shares. In the interest of economy and convenience, certificates for shares will not be issued.

The Trust and the Distributor each reserves the right, in its sole discretion, to suspend the offering of shares of the Fund or to reject any purchase order, in whole or in part, when, in the judgment of management, such suspension or rejection is in the best interests of the Trust.

Class P shares of the Trust are not qualified or registered for sale in all states. Investors should inquire as to whether shares of a particular Fund are available for offer and sale in the investor’s state of residence. Shares of the Trust may not be offered or sold in any state unless registered or qualified in that jurisdiction or unless an exemption from registration or qualification is available.

Subject to the approval of the Trust, an investor may purchase shares of the Fund with liquid securities that are eligible for purchase by the Fund (consistent with the Fund’s investment policies and restrictions) and that have a value that is readily ascertainable in accordance with the Trust’s valuation policies. These transactions will be effected only if PIMCO intends to retain the security in the Fund as an investment. Assets purchased by the Fund in such a transaction will be valued in generally the same manner as they would be valued for purposes of pricing the Fund’s shares, if such assets were included in the Fund’s assets at the time of purchase. The Trust reserves the right to amend or terminate this practice at any time.

•    Abusive Trading Practices.  The Trust encourages shareholders to invest in the Fund as part of a long-term investment strategy and discourages excessive, short-term trading and other abusive trading practices, sometimes referred to as “market timing.” However, because the Trust will not always be able to detect market timing or other abusive trading activity, investors should not assume that the Trust will be able to detect or prevent all market timing or other trading practices that may disadvantage the Fund.

Certain of the Fund’s investment strategies may expose the Fund to risks associated with market timing activities. For example, since the Fund may invest in non-U.S. securities, they may be subject to the risk that an investor may seek to take advantage of a delay between the change in value of the Fund’s non-U.S. portfolio securities and the determination of the Fund’s NAV as a result of different closing times of U.S. and non-U.S. markets by buying or selling Fund shares at a price that does not reflect their true value. A similar risk exists for the Fund’s potential investment in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities that are thinly traded and therefore may have actual values that differ from their market prices.

To discourage excessive, short-term trading and other abusive trading practices, the Trust’s Board of Trustees has adopted policies and procedures reasonably designed to detect and prevent short-term trading activity that may be harmful to the Fund and its shareholders. Such activities may have a detrimental effect on the Fund and its shareholders. For example, depending upon various factors such as the size of the Fund and the amount of its assets maintained in cash, short-term or excessive trading by Fund shareholders may interfere with the efficient management of the Fund’s portfolio, increase transaction costs and taxes, and may harm the performance of the Fund and its shareholders.

Prospectus 16

The Trust seeks to deter and prevent abusive trading practices, and to reduce these risks, through several methods. First, the Trust imposes redemption fees on shares of the Fund redeemed or exchanged within a given period after their purchase. The purpose of redemption fees is to deter excessive, short-term trading and other abusive trading practices and to help offset the costs associated with the sale of portfolio securities to satisfy redemption and exchange requests. See “Redemption Fees” below for further information. In certain situations, the Fund has elected not to impose redemption fees. See “Waiver of Redemption Fees” below for a discussion on the specific situations in which the Fund will not impose redemption fees.

Second, to the extent that there is a delay between a change in the value of a mutual fund’s portfolio holdings, and the time when that change is reflected in the NAV of the fund’s shares, the fund is exposed to the risk that investors may seek to exploit this delay by purchasing or redeeming shares at NAVs that do not reflect appropriate fair value prices. The Trust seeks to deter and prevent this activity, sometimes referred to as “stale price arbitrage,” by the appropriate use of “fair value” pricing of the Fund’s portfolio securities. See “How Fund Shares Are Priced” below for more information.

Third, the Trust seeks to monitor shareholder account activities in order to detect and prevent excessive and disruptive trading practices. The Trust and PIMCO each reserve the right to restrict or refuse any purchase or exchange transaction if, in the judgment of the Trust or of PIMCO, the transaction may adversely affect the interests of the Fund or its shareholders. Among other things, the Trust may monitor for any patterns of frequent purchases and sales that appear to be made in response to short-term fluctuations in share price, and may also monitor for any attempts to improperly avoid the imposition of redemption fees. Notice of any restrictions or rejections of transactions may vary according to the particular circumstances.

Although the Trust and its service providers seek to use these methods to detect and prevent abusive trading activities, and although the Trust will consistently apply such methods, there can be no assurances that such activities can be mitigated or eliminated. By their nature, omnibus accounts, in which purchases and sales of Fund shares by multiple investors are aggregated for presentation to the Fund on a net basis, conceal the identity of the individual investors from the Fund. This makes it more difficult for the Fund to identify short-term transactions in the Fund.

•    Retirement Plans.  Shares of the Fund are available for purchase by retirement and savings plans, including Keogh plans, 401(k) plans, 403(b) custodial accounts, and Individual Retirement Accounts. The administrator of a plan or employee benefits office can provide participants or employees with detailed information on how to participate in the plan and how to elect the Fund as an investment option. Participants in a retirement or savings plan may be permitted to elect different investment options, alter the amounts contributed to the plan, or change how contributions are allocated among investment options in accordance with the plan’s specific provisions. The plan administrator or employee benefits office should be consulted for details. For questions about participant accounts, participants should contact their employee benefits office, the plan administrator, or the organization that provides recordkeeping services for the plan. Investors who purchase shares through retirement plans should be aware that plan administrators may aggregate purchase and redemption orders for participants in the plan. Therefore, there may be a delay between the time the investor places an order with the plan administrator and the time the order is forwarded to the Transfer Agent for execution.

Redeeming Shares •    Redemptions in Writing.  An investor may redeem (sell) Class P shares by submitting a written request to PIMCO Funds, c/o BFDS Midwest, 330 W. 9th Street, Kansas City, MO 64105. The redemption request should state the Fund from which the shares are to be redeemed, the class of shares, the number or dollar amount of the shares to be redeemed and the account number. The request must be signed by the appropriate persons designated on the Client Registration Application (“Authorized Person”).

17 PIMCO Funds

Additionally, an investor may request redemptions of shares by sending a facsimile to 1-816-421-2861. Furthermore, an investor that elects to utilize e-mail redemptions on the Client Registration Application (or subsequently in writing) may request redemptions of shares by sending an e-mail to pimcoteam@bfdsmidwest.com. An Authorized Person must state the Fund and class from which the shares are to be redeemed, the number or dollar amount of the shares to be redeemed and the account number.

Neither the Trust nor the Transfer Agent may be liable for any loss, cost or expense for acting on instructions (including those by fax or e-mail) believed by the party receiving such instructions to be genuine and in accordance with the procedures described in this prospectus. Shareholders should realize that by utilizing fax or e-mail redemption, they may be giving up a measure of security that they might have if they were to redeem their shares by mail. Furthermore, interruptions in service may mean that a shareholder will be unable to effect a redemption by fax or e-mail when desired. The Transfer Agent also provides written confirmation of transactions initiated by mail, by fax or by e-mail as a procedure designed to confirm that instructions are genuine.

All redemptions, whether initiated by mail, fax or e-mail, will be processed in a timely manner, and proceeds will be forwarded by wire in accordance with the redemption policies of the Trust detailed below. See “Other Redemption Information.”

•    Redemptions by Telephone.  An investor that elects this option on the Client Registration Application (or subsequently in writing) may request redemptions of shares by calling the Trust at 1-800-927-4648. An Authorized Person must state his or her name, the Fund and class from which the shares are to be redeemed, the number or dollar amount of the shares to be redeemed and the account number. Redemption requests of an amount of $10 million or more must be submitted in writing by an Authorized Person.

In electing a telephone redemption, the investor authorizes PIMCO and the Transfer Agent to act on telephone instructions from any person representing himself to be an Authorized Person, and reasonably believed by PIMCO or the Transfer Agent to be genuine. Neither the Trust nor the Transfer Agent may be liable for any loss, cost or expense for acting on instructions (including by telephone) believed by the party receiving such instructions to be genuine and in accordance with the procedures described in this prospectus. Shareholders should realize that by electing the telephone option, they may be giving up a measure of security that they might have if they were to redeem their shares in writing. Furthermore, interruptions in service may mean that a shareholder will be unable to effect a redemption by telephone when desired. The Transfer Agent also provides written confirmation of transactions initiated by telephone as a procedure designed to confirm that telephone instructions are genuine. All telephone transactions are recorded, and PIMCO or the Transfer Agent may request certain information in order to verify that the person giving instructions is authorized to do so. The Trust or Transfer Agent may be liable for any losses due to unauthorized or fraudulent telephone transactions if it fails to employ reasonable procedures to confirm that instructions communicated by telephone are genuine. All redemptions initiated by telephone will be processed in a timely manner, and proceeds will be forwarded by wire in accordance with the redemption policies of the Trust detailed below. See “Other Redemption Information.”

An Authorized Person may decline telephone exchange or redemption privileges after an account is opened by providing the Transfer Agent a Medallion signature guaranteed letter of instruction. Shareholders may experience delays in exercising telephone redemption privileges during periods of abnormal market activity. During periods of volatile economic or market conditions, shareholders may wish to consider transmitting redemption orders by facsimile, e-mail or overnight courier.

Defined contribution plan participants may request redemptions by contacting the employee benefits office, the plan administrator or the organization that provides recordkeeping services for the plan.

Prospectus 18

•    Timing of Redemption Requests and Share Price Calculations.  A redemption request received by the Trust or its designee prior to the close of regular trading on the NYSE (normally 4:00 p.m., Eastern time), on a day the Trust is open for business, is effective on that day. A redemption request received after that time becomes effective on the next business day. Redemption requests for Fund shares are effected at the NAV per share next determined after receipt of a redemption request by the Trust or its designee, minus any applicable redemption fees. However, orders received by certain broker-dealers and other financial intermediaries on a business day prior to the close of regular trading on the NYSE and communicated to the Trust or its designee prior to such time as agreed upon by the Trust and intermediary on the following business day will be effected at the NAV determined on the prior business day. The request must properly identify all relevant information such as account number, redemption amount (in dollars or shares), the Fund name and the class of shares, and must be executed by an Authorized Person.

•    Other Redemption Information.  Redemption proceeds will ordinarily be wired to the investor’s bank within three business days after the redemption request, but may take up to seven days. Redemption proceeds will be sent by wire only to the bank name designated on the Client Registration Application. Redemptions of Fund shares may be suspended when trading on the NYSE is restricted or during an emergency which makes it impracticable for the Fund to dispose of its securities or to determine fairly the value of its net assets, or during any other period as permitted by the SEC for the protection of investors. Under these and other unusual circumstances, the Trust may suspend redemptions or postpone payment for more than seven days, as permitted by law.

For shareholder protection, a request to change information contained in an account registration (for example, a request to change the bank designated to receive wire redemption proceeds) must be received in writing, signed by an Authorized Person and accompanied by a Medallion signature guarantee from any eligible guarantor institution, as determined in accordance with the Trust’s procedures as more fully described below.

When a signature guarantee is called for, a “Medallion” signature guarantee will be required. A Medallion signature guarantee may be obtained from a domestic bank or trust company, broker, dealer, clearing agency, savings association or other financial institution which is participating in a Medallion program recognized by the Securities Transfer Association. The three recognized Medallion programs are the Securities Transfer Agents Medallion Program, Stock Exchanges Medallion Program and New York Stock Exchange, Inc. Medallion Signature Program. Signature guarantees from financial institutions which are not participating in one of these programs will not be accepted. Please note that financial institutions participating in a recognized Medallion program may still be ineligible to provide a signature guarantee for transactions of greater than a specified dollar amount. The Trust may change the signature guarantee requirements from time to time upon notice to shareholders, which may be given by means of a new or supplemented prospectus.

A Medallion signature guarantee cannot be provided by a notary public. In addition, corporations, trusts, and other institutional organizations are required to furnish evidence of the authority of the persons designated on the Client Registration Application to effect transactions for the organization.

Due to the relatively high cost of maintaining small accounts, the Trust reserves the right to redeem Class P shares in any account for their then-current value (which will be promptly paid to the investor) if at any time, due to redemption by the investor, the shares in the account do not have a value of at least $100,000. A shareholder will receive advance notice of a mandatory redemption and will be given at least 30 days to bring the value of its account up to at least $100,000.

The Trust agrees to redeem shares of the Fund solely in cash up to the lesser of $250,000 or 1% of the Fund’s net assets during any 90-day period for any one shareholder. In consideration of the best interests of the

19 PIMCO Funds

remaining shareholders, the Trust reserves the right to pay any redemption proceeds exceeding this amount in whole or in part by a distribution in kind of securities held by the Fund in lieu of cash. It is highly unlikely that shares would ever be redeemed in kind. When shares are redeemed in kind, the redeeming shareholder should expect to incur transaction costs upon the disposition of the securities received in the distribution.

Redemptions of shares held less than a certain number of days may be subject to a redemption fee. See “Redemption Fees” below.

Exchange Privilege An investor may exchange Class P shares of the Fund for shares of the same class of any other fund of the Trust that offers that class based on the respective NAVs of the shares involved. An exchange may be made by following the redemption procedure described above under “Redemptions in Writing” or, if the investor has elected the telephone redemption option, by calling the Trust at 1-800-927-4648. An investor may also exchange shares of the Fund for shares of the same class of a fund of Allianz Funds or Allianz Funds Multi-Strategy Trust. Shareholders interested in such an exchange may request a prospectus for these other funds by contacting PIMCO Funds at the same address and telephone number as the Trust.

The Trust reserves the right to refuse exchange purchases (or purchase and redemption and/or redemption and purchase transactions) if, in the judgment of PIMCO, the transaction would adversely affect the Fund and its shareholders. Although the Trust has no current intention of terminating or modifying the exchange privilege it reserves the right to do so at any time. Except as otherwise permitted by the SEC, the Trust will give you 60 days’ advance notice if it exercises its right to terminate or materially modify the exchange privilege.

Exchanges of shares held less than a certain number of days may be subject to a redemption fee. See “Redemption Fees” below.

Redemption Fees Investors in Class P shares of the Fund will be subject to a “redemption fee” on redemptions and exchanges of 2.00% of the net asset value of the shares redeemed or exchanged. Redemption fees will only be charged on shares redeemed or exchanged within 7 days (the “Holding Period”) after their acquisition, including shares acquired through exchanges.

When calculating the redemption fee, shares that are not subject to a redemption fee (“Free Shares”), including, but not limited to, shares acquired through the reinvestment of dividends and distributions, will be considered redeemed first. If Free Shares are not sufficient to fulfill the redemption order, and in cases where a shareholder holds shares acquired on different dates, the first-in/first-out (“FIFO”) method will be used to determine which additional shares are being redeemed, and therefore whether a redemption fee is payable. As a result, Free Shares will be redeemed prior to Fund shares that are subject to the fee. In cases where redemptions are processed through financial intermediaries, there may be a delay between the time the shareholder redeems his or her shares and the payment of the redemption fee to the Fund, depending upon such financial intermediaries’ trade processing procedures and systems.

A new Holding Period begins the day following each acquisition of shares through a purchase or exchange (other than a Share Class Conversion (as defined below)). For example, a series of transactions in which shares of Fund A, which is subject to a 7-day Holding Period, are exchanged for shares of Fund B, which is subject to a 30-day Holding Period, 5 days after the purchase of the Fund A shares, followed in 29 days by an exchange of the Fund B shares for shares of Fund C, will be subject to two redemption fees (one on each exchange). With respect to a Share Class Conversion (as defined below), a shareholder’s Holding Period for the class of shares purchased will include the Holding Period of the other class of shares redeemed.

The purpose of redemption fees is to deter excessive, short-term trading and other abusive trading practices as described above under “Abusive Trading Practices” and to help offset the costs associated with the sale of

Prospectus 20

portfolio securities to satisfy redemption and exchange requests made by “market timers” and other short-term shareholders, thereby insulating longer-term shareholders from such costs. Redemption fees are not paid separately, but are deducted from the amount to be received in connection with a redemption or exchange. Redemption fees are paid to and retained by the Fund to defray certain costs described above and are not paid to or retained by PIMCO or the Distributor. Redemption fees are not sales loads or contingent deferred sales charges.

Waivers of Redemption Fees.  In the following situations, the Fund has elected not to impose the redemption fee:

• redemptions and exchanges of Fund shares acquired through the reinvestment of dividends and distributions;

• redemptions or exchanges in connection with a systematic withdrawal plan (including an automatic exchange plan);

• certain types of redemptions and exchanges of Fund shares owned through participant-directed retirement plans (see below for details);

• redemptions or exchanges that are initiated by the sponsor of a program as part of a periodic rebalancing, provided that such rebalancing occurs no more frequently than monthly;

• redemptions or exchanges in a discretionary asset allocation or wrap program (“wrap programs”) that are made as a result of a full withdrawal from the wrap program;

• redemptions or exchanges by “Lifestyle Funds” (funds that have a predetermined asset mix tailored to the level of risk and return desired by particular investors) or participant accounts in defined contribution plans utilizing a similar model;

• redemptions or exchanges in connection with required minimum distributions from a wrap program, an IRA, a participant-directed retirement plan or any other employee benefit plan or account qualified under Section 401 of the Internal Revenue Code.

• redemptions or exchanges in connection with distributions from a 529 plan;

• involuntary redemptions, such as those resulting from a shareholder’s failure to maintain a minimum investment in the Fund, or to pay shareholder fees;

• redemptions and exchanges effected by other mutual funds that are sponsored by PIMCO or its affiliates; and

• otherwise as PIMCO or the Trust may determine in their sole discretion.

Additionally, no redemption fee applies to a redemption of shares of any class of the Fund where the entirety of the proceeds of such redemption are immediately invested in another share class of the same Fund (a “Share Class Conversion”).

Applicability of Redemption Fees in Certain Participant-Directed Retirement Plans.  Redemption fees will not apply to the following transactions in participant-directed retirement plans (such as 401(k), 403(b), 457 and Keogh plans): 1) where the shares being redeemed were purchased with new contributions to the plan (e.g., payroll contributions, employer contributions, loan repayments); 2) redemptions made in connection with taking out a loan from the plan; 3) redemptions in connection with death, disability, forfeiture, hardship withdrawals, or Qualified Domestic Relations Orders; 4) redemptions made by a defined contribution plan in connection with a termination or restructuring of the plan; 5) redemptions made in connection with a participant’s termination of employment; or 6) redemptions or exchanges where the application of a redemption fee would cause the Fund, or an asset allocation program of which the Fund is a part, to fail to be considered a “qualified default investment alternative” under the Employee Retirement Income Security Act of 1974, as amended, and the rules and regulations thereunder. Redemption fees generally will apply to other participant-directed redemptions and exchanges. For example, if a participant exchanges shares of Fund A that were purchased with new contributions, into Fund B, a redemption fee would not apply to that exchange. However, any subsequent

21 PIMCO Funds

participant-directed exchange of those shares from Fund B into Fund A or another fund may be subject to redemption fees, depending upon the holding period and subject to the exceptions described in this paragraph.

Retirement plan sponsors, participant recordkeeping organizations and other financial intermediaries may also impose their own restrictions, limitations or fees in connection with transactions in the Fund’s shares, which may be stricter than those described in this section. You should contact your plan sponsor, recordkeeper or financial intermediary for more information on any differences in how the redemption fee is applied to your investments in the Fund, and whether any additional restrictions, limitations or fees are imposed in connection with transactions in Fund shares.

The Trust may eliminate or modify the waivers enumerated above at any time, in its sole discretion. Shareholders will receive 60 days’ notice of any material changes to the redemption fee, unless otherwise permitted by law.

Request for Multiple Copies of Shareholder Documents To reduce expenses, it is intended that only one copy of the Fund’s prospectus and each annual and semi-annual report, when available, will be mailed to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents and your shares are held directly with the Trust, call the Trust at 1-800-927-4648. Alternatively , if your shares are held through a financial institution, please contact it directly. Within 30 days after receipt of your request by the Trust, the Trust will begin sending you individual copies.

How Fund Shares Are Priced

The NAV of the Fund’s Class P shares is determined by dividing the total value of the Fund’s portfolio investments and other assets attributable to that class, less any liabilities, by the total number of shares outstanding of that class.

Fund shares are valued as of the close of regular trading (normally 4:00 p.m., Eastern time) (the “NYSE Close”) on each day that the NYSE is open. Information that becomes known to the Fund or its agents after the NAV has been calculated on a particular day will not generally be used to retroactively adjust the price of a security or the NAV determined earlier that day.

For purposes of calculating NAV, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on the basis of last reported sales prices, or if no sales are reported, based on quotes obtained from a quotation reporting system, established market makers, or pricing services. Domestic and foreign fixed income securities and non-exchange traded derivatives are normally valued on the basis of quotes obtained from brokers and dealers or pricing services using data reflecting the earlier closing of the principal markets for those securities. Prices obtained from independent pricing services use information provided by market makers or estimates of market values obtained from yield data relating to investments or securities with similar characteristics. Certain fixed income securities purchased on a delayed-delivery basis are marked to market daily until settlement at the forward settlement date. Short term investments having a maturity of 60 days or less are generally valued at amortized cost. Exchange traded options, futures and options on futures are valued at the settlement price determined by the relevant exchange. With respect to any portion of the Fund’s assets that are invested in one or more open-end management investment companies, the Fund’s NAV will be calculated based upon the NAVs of such investments. The Fund will normally use pricing data for domestic equity securities received shortly after the NYSE Close and does not normally take into account trading, clearances or settlements that take place after the NYSE Close.

Investments initially valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from pricing services. As a result, the NAV of the Fund’s shares may be affected by changes in the value of currencies in relation to the U.S. dollar. The value of securities traded in markets outside

Prospectus 22

the United States or denominated in currencies other than the U.S. dollar may be affected significantly on a day that the NYSE is closed and an investor is not able to purchase, redeem or exchange shares.

Securities and other assets for which market quotes are not readily available are valued at fair value as determined in good faith by the Board of Trustees or persons acting at their direction. The Board of Trustees has adopted methods for valuing securities and other assets in circumstances where market quotes are not readily available, and has delegated to PIMCO the responsibility for applying the valuation methods. For instance, certain securities or investments for which daily market quotes are not readily available may be valued, pursuant to guidelines established by the Board of Trustees, with reference to other securities or indices. In the event that market quotes are not readily available, and the security or asset cannot be valued pursuant to one of the valuation methods, the value of the security or asset will be determined in good faith by the Valuation Committee of the Board of Trustees, generally based upon recommendations provided by PIMCO.

Market quotes are considered not readily available in circumstances where there is an absence of current or reliable market-based data (e.g., trade information, bid/asked information, broker quotes), including where events occur after the close of the relevant market, but prior to the NYSE Close, that materially affect the values of the Fund’s securities or assets. In addition, market quotes are considered not readily available when, due to extraordinary circumstances, the exchanges or markets on which the securities trade do not open for trading for the entire day and no other market prices are available. The Board has delegated to PIMCO the responsibility for monitoring significant events that may materially affect the values of the Fund’s securities or assets and for determining whether the value of the applicable securities or assets should be re-evaluated in light of such significant events.

When the Fund uses fair value pricing to determine its NAV, securities will not be priced on the basis of quotes from the primary market in which they are traded, but rather may be priced by another method that the Board of Trustees or persons acting at their direction believe accurately reflects fair value. Fair value pricing may require subjective determinations about the value of a security. While the Trust’s policy is intended to result in a calculation of the Fund’s NAV that fairly reflects security values as of the time of pricing, the Trust cannot ensure that fair values determined by the Board of Trustees or persons acting at their direction would accurately reflect the price that the Fund could obtain for a security if it were to dispose of that security as of the time of pricing (for instance, in a forced or distressed sale). The prices used by the Fund may differ from the value that would be realized if the securities were sold. The Fund’s use of fair valuation may also help to deter “stale price arbitrage” as discussed above under “Abusive Trading Practices.”

Fund Distributions

The Fund distributes substantially all of its net investment income to shareholders in the form of dividends. The Fund intends to declare and distribute income dividends quarterly to shareholders of record.

In addition, the Fund distributes any net capital gains it earns from the sale of portfolio securities to shareholders no less frequently than annually. Net short-term capital gains may be paid more frequently.

The Fund’s dividend and capital gain distributions with respect to a particular class of shares will automatically be reinvested in additional shares of the same class of the Fund at NAV unless the shareholder elects to have the distributions paid in cash. A shareholder may elect to have distributions paid in cash on the Client Registration Application or by submitting a written request, signed by an Authorized Person, indicating the account number, Fund name(s) and wiring instructions. Shareholders do not pay any sales charges on shares received through the reinvestment of Fund distributions.

23 PIMCO Funds

Tax Consequences

•     Taxes on Fund distributions.  A shareholder subject to U.S. federal income tax will be subject to tax on Fund distributions whether they are paid in cash or reinvested in additional shares of the Fund. For federal income tax purposes, Fund distributions will be taxable to the shareholder as either ordinary income or capital gains.

Fund dividends (i.e., distributions of investment income) are taxable to shareholders as ordinary income. Federal taxes on Fund distributions of gains are determined by how long the Fund owned the investments that generated the gains, rather than how long a shareholder has owned the shares. Distributions of gains from investments that the Fund owned for more than one year will generally be taxable to shareholders as long-term capital gains. Distributions of gains from investments that the Fund owned for one year or less will generally be taxable as ordinary income.

Fund distributions are taxable to shareholders even if they are paid from income or gains earned by the Fund prior to the shareholder’s investment and thus were included in the price paid for the shares. For example, a shareholder who purchases shares on or just before the record date of a Fund distribution will pay full price for the shares and may receive a portion of his or her investment back as a taxable distribution.

•    Taxes on redemption or exchanges of shares.  Any gain resulting from the sale of Fund shares will generally be subject to federal income tax. When a shareholder exchanges shares of the Fund for shares of another series, the transaction will be treated as a sale of the Fund shares for these purposes, and any gain on those shares will generally be subject to federal income tax.

•    Returns of capital.  If the Fund’s distributions exceed its taxable income and capital gains realized during a taxable year, all or a portion of the distributions made in the same taxable year may be recharacterized as a return of capital to shareholders. A return of capital distribution will generally not be taxable, but will reduce each shareholder’s cost basis in the Fund and result in a higher reported capital gain or lower reported capital loss when those shares on which the distribution was received are sold.

This “Tax Consequences” section relates only to federal income tax; the consequences under other tax laws may differ. Shareholders should consult their tax advisors as to the possible application of foreign, state and local income tax laws to Fund dividends and capital distributions. Please see the Statement of Additional Information for additional information regarding the tax aspects of investing in the Fund.

Characteristics and Risks of Securities and Investment Techniques

This section provides additional information about some of the principal investments and related risks of the Fund described under “Summary Information” and “Summary of Principal Risks” above. It also describes characteristics and risks of additional securities and investment techniques that may be used by the Fund from time to time. Most of these securities and investment techniques are discretionary, which means that PIMCO can decide whether to use them or not. This prospectus does not attempt to disclose all of the various types of securities and investment techniques that may be used by the Fund. As with any mutual fund, investors in the Fund rely on the professional investment judgment and skill of PIMCO and the individual portfolio manager. Please see “Investment Objectives and Policies” in the Statement of Additional Information for more detailed

Prospectus 24

information about the securities and investment techniques described in this section and about other strategies and techniques that may be used by the Fund.

Securities Selection The Fund seeks total return. The total return sought by the Fund consists of both income earned on the Fund’s investments and capital appreciation, if any, arising from increases in the market value of the Fund’s holdings. Capital appreciation of fixed income securities generally results from decreases in market interest rates, foreign

currency appreciation, or improving credit fundamentals for a particular market sector or security.

In selecting securities for the Fund, PIMCO develops an outlook for interest rates, currency exchange rates and the economy; analyzes credit and call risks, and uses other security selection techniques. The proportion of the Fund’s assets committed to investment in securities with particular characteristics (such as quality, sector, interest rate or maturity) varies based on PIMCO’s outlook for the U.S. economy and the economies of other countries in the world, the financial markets and other factors.

PIMCO attempts to identify areas of the bond market that are undervalued relative to the rest of the market. PIMCO identifies these areas by grouping bonds into sectors such as: money markets, governments, corporates, mortgages, asset-backed and international. Sophisticated proprietary software then assists in evaluating sectors and pricing specific securities. Once investment opportunities are identified, PIMCO will shift assets among sectors depending upon changes in relative valuations and credit spreads. There is no guarantee that PIMCO’s security selection techniques will produce the desired results.

U.S. Government Securities U.S. Government Securities are obligations of, or guaranteed by, the U.S. Government, its agencies or government-sponsored enterprises. U.S. Government Securities are subject to market and interest rate risk, and may be subject to varying degrees of credit risk. U.S. Government Securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities.

Municipal Bonds Municipal bonds are generally issued by states and local governments and their agencies, authorities and other instrumentalities. Municipal bonds are subject to interest rate, credit and market risk. The ability of an issuer to make payments could be affected by litigation, legislation or other political events or the bankruptcy of the issuer. Lower rated municipal bonds are subject to greater credit and market risk than higher quality municipal bonds. The types of municipal bonds in which the Fund may invest include municipal lease obligations. The Fund may also invest in industrial development bonds, which are municipal bonds issued by a government agency on behalf of a private sector company and, in most cases, are not backed by the credit of the issuing municipality and may therefore involve more risk. The Fund may also invest in securities issued by entities whose underlying assets are municipal bonds.

The Fund may invest, without limitation, in residual interest bonds (“RIBs”), which brokers create by depositing a municipal bond in a trust. The trust in turn issues a variable rate security and RIBs. The interest rate for the variable rate security is determined by an index or an auction process held approximately every 7 to 35 days, while the RIB holder receives the balance of the income from the underlying municipal bond less an auction fee. The market prices of RIBs may be highly sensitive to changes in market rates and may decrease significantly when market rates increase.

In a transaction in which the Fund purchases a RIB from a trust, and the underlying municipal bond was held by the Fund prior to being deposited into the trust, the Fund treats the transaction as a secured borrowing for financial reporting purposes. As a result, the Fund will incur a non-cash interest expense with respect to interest paid by the trust on the variable rate securities, and will recognize additional interest income in an amount directly corresponding to the non-cash interest expense. Therefore, the Fund’s NAV per share and performance

25 PIMCO Funds

are not affected by the non-cash interest expense. This accounting treatment does not apply to RIBs acquired by the Fund where the Fund did not previously own the underlying municipal bond.

Mortgage-Related and Other Asset-Backed Securities Mortgage-related securities include mortgage pass-through securities, collateralized mortgage obligations (“CMOs”), commercial mortgage-backed securities, mortgage dollar rolls, CMO residuals, stripped mortgage-backed securities (“SMBSs”) and other securities that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property.

The value of some mortgage- or asset-backed securities may be particularly sensitive to changes in prevailing interest rates. Early repayment of principal on some mortgage-related securities may expose the Fund to a lower rate of return upon reinvestment of principal. When interest rates rise, the value of a mortgage-related security generally will decline; however, when interest rates are declining, the value of mortgage-related securities with prepayment features may not increase as much as other fixed income securities. The rate of prepayments on underlying mortgages will affect the price and volatility of a mortgage-related security, and may shorten or extend the effective maturity of the security beyond what was anticipated at the time of purchase. If unanticipated rates of prepayment on underlying mortgages increase the effective maturity of a mortgage-related security, the volatility of the security can be expected to increase. The value of these securities may fluctuate in response to the market’s perception of the creditworthiness of the issuers. Additionally, although mortgages and mortgage-related securities are generally supported by some form of government or private guarantee and/or insurance, there is no assurance that private guarantors or insurers will meet their obligations.

One type of SMBS has one class receiving all of the interest from the mortgage assets (the interest-only, or “IO” class), while the other class will receive all of the principal (the principal-only, or “PO” class). The yield to maturity on an IO class is extremely sensitive to the rate of principal payments (including prepayments) on the underlying mortgage assets, and a rapid rate of principal payments may have a material adverse effect on a Fund’s yield to maturity from these securities. The Fund may invest up to 5% of its total assets in any combination of mortgage-related or other asset-backed IO, PO or inverse floater securities.

The Fund may invest in collateralized debt obligations (“CDOs”), which include collateralized bond obligations (“CBOs”), collateralized loan obligations (“CLOs”) and other similarly structured securities. A CBO is a trust which is backed by a diversified pool of high risk, below investment grade fixed income securities. A CLO is a trust typically collateralized by a pool of loans, which may include, among others, domestic and foreign senior secured loans, senior unsecured loans, and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans. The Fund may invest in other asset-backed securities that have been offered to investors.

Loan Participations and Assignments The Fund may invest in fixed- and floating-rate loans, which investments generally will be in the form of loan participations and assignments of portions of such loans. Participations and assignments involve special types of risk, including credit risk, interest rate risk, liquidity risk, and the risks of being a lender. If the Fund purchases a participation, it may only be able to enforce its rights through the lender, and may assume the credit risk of the lender in addition to the borrower.

Corporate Debt Securities Corporate debt securities are subject to the risk of the issuer’s inability to meet principal and interest payments on the obligation and may also be subject to price volatility due to such factors as interest rate sensitivity, market perception of the creditworthiness of the issuer and general market liquidity. When interest rates rise, the value of corporate debt securities can be expected to decline. Debt securities with longer maturities tend to be more sensitive to interest rate movements than those with shorter maturities.

Prospectus 26

High Yield Securities Securities rated lower than Baa by Moody’s, or equivalently rated by S&P or Fitch, are sometimes referred to as “high yield securities” or “junk bonds”. Investing in these securities involves special risks in addition to the risks associated with investments in higher-rated fixed income securities. While offering a greater potential opportunity for capital appreciation and higher yields, high yield securities typically entail greater potential price volatility and may be less liquid than higher-rated securities. High yield securities may be regarded as predominately speculative with respect to the issuer’s continuing ability to meet principal and interest payments. They may also be more susceptible to real or perceived adverse economic and competitive industry conditions than higher-rated securities. Issuers of securities in default may fail to resume principal or interest payments, in which case the Fund may lose its entire investment.

Variable and Floating Rate Securities Variable and floating rate securities provide for a periodic adjustment in the interest rate paid on the obligations. The Fund may invest in floating rate debt instruments (“floaters”) and engage in credit spread trades. Variable and floating rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Conversely, floating rate securities will not generally increase in value if interest rates decline. The Fund may also invest in inverse floating rate debt instruments (“inverse floaters”). An inverse floater may exhibit greater price volatility than a fixed rate obligation of similar credit quality. The Fund may invest up to 5% of its total assets in any combination of mortgage-related or other asset-backed IO, PO or inverse floater securities. Additionally, the Fund may also invest, without limitation, in RIBs.

Inflation-Indexed Bonds Inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds, which are more fully described below) are fixed income securities whose principal value is periodically adjusted according to the rate of inflation. If the index measuring inflation falls, the principal value of inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds) will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced. Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal.

With regard to municipal inflation-indexed bonds and certain corporate inflation-indexed bonds, the inflation adjustment is reflected in the semi-annual coupon payment. As a result, the principal value of municipal inflation-indexed bonds and such corporate inflation-indexed bonds does not adjust according to the rate of inflation.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation-indexed bonds. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Event-Linked Exposure The Fund may obtain event-linked exposure by investing in “event-linked bonds” or “event-linked swaps” or implement “event-linked strategies.” Event-linked exposure results in gains or losses that typically are contingent, or formulaically related to defined trigger events. Examples of trigger events include hurricanes, earthquakes, weather-related phenomena, or statistics relating to such events. Some event-linked bonds are commonly referred to as “catastrophe bonds.” If a trigger event occurs, the Fund may lose a portion or its entire principal invested in the bond or notional amount on a swap. Event-linked exposure often provides for an

27 PIMCO Funds

extension of maturity to process and audit loss claims where a trigger event has, or possibly has, occurred. An extension of maturity may increase volatility. Event-linked exposure may also expose the Fund to certain unanticipated risks including credit risk, counterparty risk, adverse regulatory or jurisdictional interpretations, and adverse tax consequences. Event-linked exposures may also be subject to liquidity risk.

Convertible and Equity Securities The Fund may invest in convertible securities and equity securities. Convertible securities are generally preferred stocks and other securities, including fixed income securities and warrants, that are convertible into or exercisable for common stock at a stated price or rate. The price of a convertible security will normally vary in some proportion to changes in the price of the underlying common stock because of this conversion or exercise feature. However, the value of a convertible security may not increase or decrease as rapidly as the underlying common stock. A convertible security will normally also provide income and is subject to interest rate risk. Convertible securities may be lower-rated securities subject to greater levels of credit risk. The Fund may be forced to convert a security before it would otherwise choose, which may have an adverse effect on the Fund’s ability to achieve its investment objective.

Preferred stock represents an equity interest in a company that generally entitles the holder to receive, in preference to the holders of other stocks such as common stocks, dividends and a fixed share of the proceeds resulting from a liquidation of the company. Preferred stocks may pay fixed or adjustable rates of return. Preferred stock is subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company’s preferred stock generally pays dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred stock will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects.

While some countries or companies may be regarded as favorable investments, pure fixed income opportunities may be unattractive or limited due to insufficient supply, or legal or technical restrictions. In such cases, subject to its applicable investment restrictions, the Fund may consider convertible securities or equity securities to gain exposure to such investments.

While the Fund will generally invest in equity derivatives, the Fund may also invest without limitation directly in equity securities, including common stocks, preferred stocks and convertible securities. When investing directly in equity securities, the Fund will not be limited to only those equity securities with any particular weighting in the Fund’s benchmark index, if any. Generally, the Fund may consider investing directly in equity securities when derivatives on the underlying securities appear to be overvalued.

At times, in connection with the restructuring of a Fixed Income Instrument either outside of bankruptcy court or in the context of bankruptcy court proceedings, the Fund may determine or be required to accept equity securities in exchange for all or a portion of a Fixed Income Instrument. Depending upon, among other things, PIMCO’s evaluation of the potential value of such securities in relation to the price that could be obtained by a Fund at any given time upon sale thereof, the Fund may determine to hold such securities in its portfolio.

Equity securities generally have greater price volatility than fixed income securities. The market price of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. Equity securities may decline in value due to factors affecting equity securities markets generally or particular industries represented in those markets. The value of an equity security may also decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services.

Prospectus 28

Foreign (Non-U.S.) Securities The Fund may invest in securities and instruments that are economically tied to foreign (non-U.S.) countries. PIMCO generally considers an instrument to be economically tied to a non-U.S. country if the issuer is a foreign government (or any political subdivision, agency, authority or instrumentality of such government), or if the issuer is organized under the laws of a non-U.S. country. In the case of certain money market instruments, such instruments will be considered economically tied to a non-U.S. country if either the issuer or the guarantor of such money market instrument is organized under the laws of a non-U.S. country. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to non-U.S. countries if the underlying assets are foreign currencies (or baskets or indexes of such currencies), or instruments or securities that are issued by foreign governments or issuers organized under the laws of a non-U.S. country (or if the underlying assets are certain money market instruments, if either the issuer or the guarantor of such money market instruments is organized under the laws of a non-U.S. country).

Investing in foreign securities involves special risks and considerations not typically associated with investing in U.S. securities. Shareholders should consider carefully the substantial risks involved for funds that invest in securities issued by foreign companies and governments of foreign countries. These risks include: differences in accounting, auditing and financial reporting standards; generally higher commission rates on foreign portfolio transactions; the possibility of nationalization, expropriation or confiscatory taxation; adverse changes in investment or exchange control regulations; and political instability. Individual foreign economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross domestic product, rates of inflation, capital reinvestment, resources, self-sufficiency and balance of payments position. The securities markets, values of securities, yields and risks associated with foreign securities markets may change independently of each other. Also, foreign securities and dividends and interest payable on those securities may be subject to foreign taxes, including taxes withheld from payments on those securities. Foreign securities often trade with less frequency and volume than domestic securities and therefore may exhibit greater price volatility. Investments in foreign securities may also involve higher custodial costs than domestic investments and additional transaction costs with respect to foreign currency conversions. Changes in foreign exchange rates also will affect the value of securities denominated or quoted in foreign currencies.

The Fund also may invest in sovereign debt issued by governments, their agencies or instrumentalities, or other government-related entities. Holders of sovereign debt may be requested to participate in the rescheduling of such debt and to extend further loans to governmental entities. In addition, there is no bankruptcy proceeding by which defaulted sovereign debt may be collected.

•     Emerging Market Securities.  The Fund may invest in securities and instruments that are economically tied to emerging market countries. PIMCO generally considers an instrument to be economically tied to an emerging market country if the issuer or guarantor is a government of an emerging market country (or any political subdivision, agency, authority or instrumentality of such government), if the issuer or guarantor is organized under the laws of an emerging market country, or if the currency of settlement of the security is a currency of an emerging market country. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to emerging market countries if the underlying assets are currencies of emerging market countries (or baskets or indexes of such currencies), or instruments or securities that are issued or guaranteed by governments of emerging market countries or by entities organized under the laws of emerging market countries. PIMCO has broad discretion to identify countries that it considers to qualify as emerging markets. In making investments in emerging market securities, the Fund emphasizes those countries with relatively low gross national product per capita and with the potential for rapid economic growth. Emerging market countries are generally located in Asia, Africa, the Middle East, Latin America and Eastern Europe. PIMCO will select the country and currency composition based on its evaluation of relative interest rates,

29 PIMCO Funds

inflation rates, exchange rates, monetary and fiscal policies, trade and current account balances, and any other specific factors it believes to be relevant.

Investing in emerging market securities imposes risks different from, or greater than, risks of investing in domestic securities or in foreign, developed countries. These risks include: smaller market capitalization of securities markets, which may suffer periods of relative illiquidity; significant price volatility; restrictions on foreign investment; possible repatriation of investment income and capital. In addition, foreign investors may be required to register the proceeds of sales; future economic or political crises could lead to price controls, forced mergers, expropriation or confiscatory taxation, seizure, nationalization, or creation of government monopolies. The currencies of emerging market countries may experience significant declines against the U.S. dollar, and devaluation may occur subsequent to investments in these currencies by a Fund. Inflation and rapid fluctuations in inflation rates have had, and may continue to have, negative effects on the economies and securities markets of certain emerging market countries.

Additional risks of emerging markets securities may include: greater social, economic and political uncertainty and instability; more substantial governmental involvement in the economy; less governmental supervision and regulation; unavailability of currency hedging techniques; companies that are newly organized and small; differences in auditing and financial reporting standards, which may result in unavailability of material information about issuers; and less developed legal systems. In addition, emerging securities markets may have different clearance and settlement procedures, which may be unable to keep pace with the volume of securities transactions or otherwise make it difficult to engage in such transactions. Settlement problems may cause the Fund to miss attractive investment opportunities, hold a portion of its assets in cash pending investment, or be delayed in disposing of a portfolio security. Such a delay could result in possible liability to a purchaser of the security.

The Fund may invest in Brady Bonds, which are securities created through the exchange of existing commercial bank loans to sovereign entities for new obligations in connection with a debt restructuring. Investments in Brady Bonds may be viewed as speculative. Brady Bonds acquired by the Fund may be subject to restructuring arrangements or to requests for new credit, which may cause the Fund to suffer a loss of interest or principal on any of its holdings of relevant Brady Bonds.

Foreign (Non-U.S.) Currencies The Fund may invest directly in foreign currencies or in securities that trade in, or receive revenues in, foreign currencies, and will be subject to currency risk. Foreign currency exchange rates may fluctuate significantly over short periods of time. They generally are determined by supply and demand in the foreign exchange markets and the relative merits of investments in different countries, actual or perceived changes in interest rates and other complex factors. Currency exchange rates also can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments.

•     Foreign Currency Transactions.  The Fund may invest in securities denominated in foreign currencies, engage in foreign currency transactions on a spot (cash) basis, and enter into forward foreign currency exchange contracts and invest in foreign currency futures contracts and options on foreign currencies and futures. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, reduces the Fund’s exposure to changes in the value of the currency it will deliver and increases its exposure to changes in the value of the currency it will receive for the duration of the contract. Certain foreign currency transactions may also be settled in cash rather than the actual delivery of the relevant currency. The effect on the value of the Fund is similar to selling securities denominated in one currency and purchasing securities denominated in another currency. A contract to sell

Prospectus 30

foreign currency would limit any potential gain which might be realized if the value of the hedged currency increases. The Fund may enter into these contracts to hedge against foreign exchange risk, to increase exposure to a foreign currency or to shift exposure to foreign currency fluctuations from one currency to another. Suitable hedging transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in such transactions at any given time or from time to time. Also, such transactions may not be successful and may eliminate any chance for the Fund to benefit from favorable fluctuations in relevant foreign currencies. The Fund may use one currency (or a basket of currencies) to hedge against adverse changes in the value of another currency (or a basket of currencies) when exchange rates between the two currencies are positively correlated. The Fund will segregate or “earmark” assets determined to be liquid by PIMCO in accordance with the procedures established by the Board of Trustees (or, as permitted by applicable law, enter into certain offsetting positions) to cover its obligations under forward foreign currency exchange contracts entered into for non-hedging purposes.

Repurchase Agreements The Fund may enter into repurchase agreements, in which the Fund purchases a security from a bank or broker-dealer, which agrees to repurchase the security at the Fund’s cost plus interest within a specified time. If the party agreeing to repurchase should default, the Fund will seek to sell the securities which it holds. This could involve procedural costs or delays in addition to a loss on the securities if their value should fall below their repurchase price. Repurchase agreements maturing in more than seven days are considered illiquid securities.

Reverse Repurchase Agreements, Dollar Rolls and Other Borrowings The Fund may enter into reverse repurchase agreements and dollar rolls, subject to the Fund’s limitations on borrowings. A reverse repurchase agreement or dollar roll involves the sale of a security by the Fund and its agreement to repurchase the instrument at a specified time and price, and may be considered a form of borrowing for some purposes. The Fund will segregate or “earmark” assets determined to be liquid by PIMCO to cover its obligations under reverse repurchase agreements and dollar rolls. Reverse repurchase agreements, dollar rolls and other forms of borrowings may create leveraging risk for the Fund.

The Fund may borrow money to the extent permitted under the 1940 Act. This means that, in general, the Fund may borrow money from banks for any purpose in an amount up to 1/3 of the Fund’s total assets. The Fund may also borrow money for temporary administrative purposes in an amount not to exceed 5% of the Fund’s total assets.

Derivatives The Fund may, but is not required to, use derivative instruments for risk management purposes or as part of its investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate or index, and may relate to stocks, bonds, interest rates, currencies or currency exchange rates, commodities, and related indexes. Examples of derivative instruments include options contracts, futures contracts, options on futures contracts and swap agreements (including, but not limited to, credit default swaps and swaps on exchange traded funds). The Fund may invest some or all of its assets in derivative instruments. The portfolio manager may decide not to employ any of these strategies and there is no assurance that any derivatives strategy used by the Fund will succeed. A description of these and other derivative instruments that the Fund may use are described under “Investment Objectives and Policies” in the Statement of Additional Information.

The Fund’s use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other more traditional investments. A description of various risks associated with particular derivative instruments is included in “Investment Objectives and Policies” in the Statement of Additional Information. The following provides a more general discussion of important risk factors relating to all derivative instruments that may be used by the Fund.

31 PIMCO Funds

Management Risk. Derivative products are highly specialized instruments that require investment techniques and risk analyses different from those associated with stocks and bonds. The use of a derivative requires an understanding not only of the underlying instrument but also of the derivative itself, without the benefit of observing the performance of the derivative under all possible market conditions.

Credit Risk. The use of a derivative instrument involves the risk that a loss may be sustained as a result of the failure of another party to the contract (usually referred to as a “counterparty”) to make required payments or otherwise comply with the contract’s terms. Additionally, credit default swaps could result in losses if the Fund does not correctly evaluate the creditworthiness of the company on which the credit default swap is based.

Liquidity Risk. Liquidity risk exists when a particular derivative instrument is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid (as is the case with many privately negotiated derivatives), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price.

Leverage Risk. Because many derivatives have a leverage component, adverse changes in the value or level of the underlying asset, reference rate or index can result in a loss substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. When the Fund uses derivatives for leverage, investments in the Fund will tend to be more volatile, resulting in larger gains or losses in response to market changes. To limit leverage risk, the Fund will segregate or “earmark” assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees (or, as permitted by applicable regulation, enter into certain offsetting positions) to cover its obligations under derivative instruments.

Lack of Availability. Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, suitable derivatives transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, the portfolio manager may wish to retain the Fund’s position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other suitable counterparty can be found. There is no assurance that the Fund will engage in derivatives transactions at any time or from time to time. The Fund’s ability to use derivatives may also be limited by certain regulatory and tax considerations.

Market and Other Risks. Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to the Fund’s interest. If the portfolio manager incorrectly forecasts the values of securities, currencies or interest rates or other economic factors in using derivatives for the Fund, the Fund might have been in a better position if it had not entered into the transaction at all. While some strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other Fund investments. The Fund may also have to buy or sell a security at a disadvantageous time or price because the Fund is legally required to maintain offsetting positions or asset coverage in connection with certain derivatives transactions.

Other risks in using derivatives include the risk of mispricing or improper valuation of derivatives and the inability of derivatives to correlate perfectly with underlying assets, rates and indexes. Many derivatives, in particular privately negotiated derivatives, are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to the Fund. Also, the value of derivatives may not correlate perfectly, or at all, with the value of the assets, reference rates or indexes they are

Prospectus 32

designed to closely track. For example, a swap agreement on an exchange traded fund would not correlate perfectly with the index upon which the exchange traded fund is based because the fund’s return is net of fees and expenses. In addition, the Fund’s use of derivatives may cause the Fund to realize higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if the Fund had not used such instruments.

Exchange-Traded Notes The Fund may invest in exchange-traded notes (“ETNs”). ETNs are senior, unsecured, unsubordinated debt securities whose returns are linked to the performance of a particular market benchmark or strategy minus applicable fees. ETNs are traded on an exchange (e.g., the NYSE) during normal trading hours. However, investors can also hold the ETN until maturity. At maturity, the issuer pays to the investor a cash amount equal to the principal amount, subject to the day’s market benchmark or strategy factor.

ETNs do not make periodic coupon payments or provide principal protection. ETNs are subject to credit risk and the value of the ETN may drop due to a downgrade in the issuer’s credit rating, despite the underlying market benchmark or strategy remaining unchanged. The value of an ETN may also be influenced by time to maturity, level of supply and demand for the ETN, volatility and lack of liquidity in underlying assets, changes in the applicable interest rates, changes in the issuer’s credit rating, and economic, legal, political, or geographic events that affect the referenced underlying asset. When the Fund invests in ETNs it will bear its proportionate share of any fees and expenses borne by the ETN. The Fund’s decision to sell its ETN holdings may be limited by the availability of a secondary market. ETNs are also subject to tax risk. The IRS and Congress are considering proposals that would change the timing and character of income and gains from ETNs. There may be times when an ETN share trades at a premium or discount to its market benchmark or strategy.

Delayed Funding Loans and Revolving Credit Facilities The Fund may also enter into, or acquire participations in, delayed funding loans and revolving credit facilities, in which a lender agrees to make loans up to a maximum amount upon demand by the borrower during a specified term. These commitments may have the effect of requiring the Fund to increase its investment in a company at a time when it might not otherwise decide to do so (including at a time when the company’s financial condition makes it unlikely that such amounts will be repaid). To the extent that the Fund is committed to advance additional funds, it will segregate or “earmark” assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees in an amount sufficient to meet such commitments. Delayed funding loans and revolving credit facilities are subject to credit, interest rate and liquidity risk and the risks of being a lender.

When-Issued, Delayed Delivery and Forward Commitment Transactions The Fund may purchase securities which it is eligible to purchase on a when-issued basis, may purchase and sell such securities for delayed delivery and may make contracts to purchase such securities for a fixed price at a future date beyond normal settlement time (forward commitments). When-issued transactions, delayed delivery purchases and forward commitments involve a risk of loss if the value of the securities declines prior to the settlement date. This risk is in addition to the risk that the Fund’s other assets will decline in value. Therefore, these transactions may result in a form of leverage and increase the Fund’s overall investment exposure. Typically, no income accrues on securities the Fund has committed to purchase prior to the time delivery of the securities is made, although the Fund may earn income on securities it has segregated or “earmarked” to cover these positions.

Investment in Other Investment Companies Except as described below, the Fund may invest up to 10% of its total assets in securities of other investment companies, such as open-end or closed-end management investment companies, or in pooled accounts or other investment vehicles which invest in foreign markets. As a shareholder of an investment company, the Fund may indirectly bear service and other fees which are in addition to the fees the Fund pays its service providers.

33 PIMCO Funds

The Fund may invest in the PIMCO Funds Private Account Portfolio Series: Short-Term Floating NAV Portfolio (“PAPS Short-Term Floating NAV Portfolio”), to the extent permitted by the 1940 Act, the rules thereunder or exemptive relief therefrom. The PAPS Short-Term Floating NAV Portfolio is a registered investment company created for use solely by the series of the Trust and series of the PIMCO Variable Insurance Trust, another series of registered investment companies advised by PIMCO, in connection with their cash management activities. The main investments of the PAPS Short-Term Floating NAV Portfolio are money market instruments and short maturity Fixed Income Instruments. The PAPS Short-Term Floating NAV Portfolio may incur expenses related to its investment activities, but does not pay investment advisory or supervisory and administrative fees to PIMCO.

Subject to the restrictions and limitations of the 1940 Act, the Fund may elect to pursue its investment objective either by investing directly in securities, or by investing in one or more underlying investment vehicles or companies that have substantially similar investment objectives and policies as the Fund. The Fund may also invest in exchange traded funds, subject to the restrictions and limitations of the 1940 Act.

Short Sales The Fund may make short sales as part of its overall portfolio management strategies or to offset a potential decline in value of a security. A short sale involves the sale of a security that is borrowed from a broker or other institution to complete the sale. Short sales expose the Fund to the risk that it will be required to acquire, convert or exchange securities to replace the borrowed securities (also known as “covering” the short position) at a time when the securities sold short have appreciated in value, thus resulting in a loss to the Fund. When making a short sale, the Fund must segregate or “earmark” assets determined to be liquid by PIMCO in accordance with procedures established by the Board of Trustees or otherwise cover its position in a permissible manner. The Fund may engage in short selling to the extent permitted by the 1940 Act and rules and interpretations thereunder and other federal securities laws. To the extent the Fund engages in short selling in foreign (non-U.S.) jurisdictions, the Fund will do so to the extent permitted by the laws and regulations of such jurisdictions.

Illiquid Securities The Fund may invest up to 15% of its net assets in illiquid securities. Certain illiquid securities may require pricing at fair value as determined in good faith under the supervision of the Board of Trustees. A portfolio manager may be subject to significant delays in disposing of illiquid securities, and transactions in illiquid securities may entail registration expenses and other transaction costs that are higher than those for transactions in liquid securities. The term “illiquid securities” for this purpose means securities that cannot be disposed of within seven days in the ordinary course of business at approximately the amount at which the Fund has valued the securities. Restricted securities, i.e., securities subject to legal or contractual restrictions on resale, may be illiquid. However, some restricted securities (such as securities issued pursuant to Rule 144A under the Securities Act of 1933, as amended, and certain commercial paper) may be treated as liquid, although they may be less liquid than registered securities traded on established secondary markets.

Loans of Portfolio Securities For the purpose of achieving income, the Fund may lend its portfolio securities to brokers, dealers, and other financial institutions provided a number of conditions are satisfied, including that the loan is fully collateralized. Please see “Investment Objectives and Policies” in the Statement of Additional Information for details. When the Fund lends portfolio securities, its investment performance will continue to reflect changes in the value of the securities loaned, and the Fund will also receive a fee or interest on the collateral. Securities lending involves the risk of loss of rights in the collateral or delay in recovery of the collateral if the borrower fails to return the security loaned or becomes insolvent. The Fund may pay lending fees to a party arranging the loan.

Prospectus 34

Portfolio Turnover The length of time the Fund has held a particular security is not generally a consideration in investment decisions. A change in the securities held by the Fund is known as “portfolio turnover.” The Fund may engage in frequent and active trading of portfolio securities to achieve its investment objective, particularly during periods of volatile market movements. High portfolio turnover (e.g., over 100%) involves correspondingly greater expenses to the Fund, including brokerage commissions or dealer mark-ups and other transaction costs on the sale of securities and reinvestments in other securities. Such sales may also result in realization of taxable capital gains, including short-term capital gains (which are generally taxed at ordinary income tax rates). The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.

Temporary Defensive Strategies For temporary or defensive purposes, the Fund may invest without limit in U.S. debt securities, including taxable securities and short-term money market securities, when PIMCO deems it appropriate to do so. When the Fund engages in such strategies, it may not achieve its investment objective.

Changes in Investment Objective and Policies The investment objective of the Fund is non-fundamental and may be changed by the Board of Trustees without shareholder approval. Unless otherwise stated, all investment policies of the Fund may be changed by the Board of Trustees without shareholder approval.

Percentage Investment Limitations Unless otherwise stated, all percentage limitations on Fund investments listed in this prospectus will apply at the time of investment. The Fund would not violate these limitations unless an excess or deficiency occurs or exists immediately after and as a result of an investment.

Credit Ratings and Unrated Securities Rating agencies are private services that provide ratings of the credit quality of fixed income securities, including convertible securities. Appendix A to this prospectus describes the various ratings assigned to fixed income securities by Moody’s, S&P and Fitch. Ratings assigned by a rating agency are not absolute standards of credit quality and do not evaluate market risks. Rating agencies may fail to make timely changes in credit ratings and an issuer’s current financial condition may be better or worse than a rating indicates. The Fund will not necessarily sell a security when its rating is reduced below its rating at the time of purchase. PIMCO does not rely solely on credit ratings, and develops its own analysis of issuer credit quality.

The Fund may purchase unrated securities (which are not rated by a rating agency) if its portfolio manager determines that the security is of comparable quality to a rated security that the Fund may purchase. Unrated securities may be less liquid than comparable rated securities and involve the risk that the portfolio manager may not accurately evaluate the security’s comparative credit rating. Analysis of the creditworthiness of issuers of high yield securities may be more complex than for issuers of higher-quality fixed income securities. To the extent that the Fund invests in high yield and/or unrated securities, the Fund’s success in achieving its investment objective may depend more heavily on the portfolio manager’s creditworthiness analysis than if the Fund invested exclusively in higher-quality and rated securities.

Other Investments and Techniques The Fund may invest in other types of securities and use a variety of investment techniques and strategies which are not described in this prospectus. These securities and techniques may subject the Fund to additional risks. Please see the Statement of Additional Information for additional information about the securities and investment techniques described in this prospectus and about additional securities and techniques that may be used by the Fund.

35 PIMCO Funds

Financial Highlights

Because the Fund had not commenced operations during the fiscal year ended March 31, 2008, financial performance information is not provided.

Prospectus 36

Appendix A

Description of Securities Ratings

The Fund’s investments may range in quality from securities rated in the lowest category to securities rated in the highest category (as rated by Moody’s, S&P, or Fitch, or, if unrated, determined by PIMCO to be of comparable quality). The percentage of the Fund’s assets invested in securities in a particular rating category will vary. The following terms are generally used to describe the credit quality of fixed income securities:

High Quality Debt Securities are those rated in one of the two highest rating categories (the highest category for commercial paper) or, if unrated, deemed comparable by PIMCO.

Investment Grade Debt Securities are those rated in one of the four highest rating categories or, if unrated, deemed comparable by PIMCO.

Below Investment Grade, High Yield Securities (“Junk Bonds”) are those rated lower than Baa by Moody’s, BBB by S&P or Fitch and comparable securities. They are considered predominantly speculative with respect to the issuer’s ability to repay principal and interest.

The following is a description of Moody’s, S&P’s and Fitch’s rating categories applicable to fixed income securities.

Moody’s Investors Service, Inc. Long-Term Obligation Ratings

Moody’s long-term obligation ratings are opinions of the relative credit risk of fixed-income obligations with an original maturity of one year or more. They address the possibility that a financial obligation will not be honored as promised. Such ratings reflect both the likelihood of default and any financial loss suffered in the event of default.

Aaa: Obligations rated Aaa are judged to be of the highest quality, with minimal credit risk.

Aa: Obligations rated Aa are judged to be of high quality and are subject to very low credit risk.

A: Obligations rated A are considered upper-medium grade and are subject to low credit risk.

Baa: Obligations rated Baa are subject to moderate credit risk. They are considered medium-grade and as such may possess certain speculative characteristics.

Ba: Obligations rated Ba are judged to have speculative elements and are subject to substantial credit risk.

B: Obligations rated B are considered speculative and are subject to high credit risk.

Caa: Obligations rated Caa are judged to be of poor standing and are subject to very high credit risk.

Ca: Obligations rated Ca are highly speculative and are likely in, or very near, default, with some prospect of recovery of principal and interest.

C: Obligations rated C are the lowest rated class of bonds and are typically in default, with little prospect for recovery of principal or interest.

Moody’s appends numerical modifiers 1, 2, and 3 to each generic rating classification from Aa through Caa. The modifier 1 indicates that the obligation ranks in the higher end of its generic rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking in the lower end of that generic rating category.

A-1 PIMCO Funds

Short-Term Ratings

Moody’s short-term ratings are opinions of the ability of issuers to honor short-term financial obligations. Ratings may be assigned to issuers, short-term programs or to individual short-term debt instruments. Such obligations generally have an original maturity not exceeding thirteen months, unless explicitly noted.

Moody’s employs the following designations to indicate the relative repayment ability of rated issuers:

P-1: Issuers (or supporting institutions) rated Prime-1 have a superior ability to repay short-term debt obligations.

P-2: Issuers (or supporting institutions) rated Prime-2 have a strong ability to repay short-term debt obligations.

P-3: Issuers (or supporting institutions) rated Prime-3 have an acceptable ability to repay short-term obligations.

NP: Issuers (or supporting institutions) rated Not Prime do not fall within any of the Prime rating categories.

US Municipal Short-Term Debt and Demand Obligation Ratings

Short-Term Debt Ratings

There are three rating categories for short-term municipal obligations that are considered investment grade. These ratings are designated as Municipal Investment Grade (MIG) and are divided into three levels—MIG 1 through MIG 3. In addition, those short-term obligations that are of speculative quality are designated SG, or speculative grade. MIG ratings expire at the maturity of the obligation.

MIG 1: This designation denotes superior credit quality. Excellent protection is afforded by established cash flows, highly reliable liquidity support, or demonstrated broad-based access to the market for refinancing.

MIG 2: This designation denotes strong credit quality. Margins of protection are ample, although not as large as in the preceding group.

MIG 3: This designation denotes acceptable credit quality. Liquidity and cash-flow protection may be narrow, and market access for refinancing is likely to be less well-established.

SG: This designation denotes speculative-grade credit quality. Debt instruments in this category may lack sufficient margins of protection.

Demand Obligation Ratings

In the case of variable rate demand obligations (VRDOs), a two-component rating is assigned; a long or short-term debt rating and a demand obligation rating. The first element represents Moody’s evaluation of the degree of risk associated with scheduled principal and interest payments. The second element represents Moody’s evaluation of the degree of risk associated with the ability to receive purchase price upon demand (“demand feature”), using a variation of the MIG rating scale, the Variable Municipal Investment Grade or VMIG rating. When either the long- or short-term aspect of a VRDO is not rated, that piece is designated NR, e.g., Aaa/NR or NR/VMIG 1. VMIG rating expirations are a function of each issue’s specific structural or credit features.

VMIG 1: This designation denotes superior credit quality. Excellent protection is afforded by the superior short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

VMIG 2: This designation denotes strong credit quality. Good protection is afforded by the strong short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

Prospectus A-2

VMIG 3: This designation denotes acceptable credit quality. Adequate protection is afforded by the satisfactory short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.

SG: This designation denotes speculative-grade credit quality. Demand features rated in this category may be supported by a liquidity provider that does not have an investment grade short-term rating or may lack the structural and/or legal protections necessary to ensure the timely payment of purchase price upon demand.

Standard & Poor’s Ratings Services Corporate and Municipal Bond Ratings

Investment Grade

AAA: An obligation rated ‘AAA’ has the highest rating assigned by Standard & Poor’s. The obligor’s capacity to meet its financial commitment on the obligation is extremely strong.

AA: An obligation rated ‘AA’ differs from the highest-rated obligations only to a small degree. The obligor’s capacity to meet its financial commitment on the obligation is very strong.

A: An obligation rated ‘A’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher-rated categories. However, the obligor’s capacity to meet its financial commitment on the obligation is still strong.

BBB: An obligation rated ‘BBB’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.

Speculative Grade

Obligations rated ‘BB’, ‘B’, ‘CCC’, ‘CC’, and ‘C’ are regarded as having significant speculative characteristics. ‘BB’ indicates the least degree of speculation and ‘C’ the highest. While such obligations will likely have some quality and protective characteristics, these may be outweighed by large uncertainties or major exposures to adverse conditions.

BB: An obligation rated ‘BB’ is less vulnerable to nonpayment than other speculative issues. However, it faces major ongoing uncertainties or exposure to adverse business, financial, or economic conditions which could lead to the obligor’s inadequate capacity to meet its financial commitment on the obligation.

B: An obligation rated ‘B’ is more vulnerable to nonpayment than obligations rated ‘BB’, but the obligor currently has the capacity to meet its financial commitment on the obligation. Adverse business, financial, or economic conditions will likely impair the obligor’s capacity or willingness to meet its financial commitment on the obligation.

CCC: An obligation rated ‘CCC’ is currently vulnerable to nonpayment, and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation. In the event of adverse business, financial, or economic conditions, the obligor is not likely to have the capacity to meet its financial commitment on the obligation.

CC: An obligation rated ‘CC’ is currently highly vulnerable to nonpayment.

C: A subordinated debt or preferred stock obligation rated ‘C’ is currently highly vulnerable to nonpayment. The ‘C’ rating may be used to cover a situation where a bankruptcy petition has been filed or similar action taken, but payments on this obligation are being continued. A ‘C’ also will be assigned to a preferred stock issue in arrears on dividends or sinking fund payments, but that is currently paying.

D: An obligation rated ‘D’ is in payment default. The ‘D’ rating category is used when payments on an obligation are not made on the date due even if the applicable grace period has not expired, unless

A-3 PIMCO Funds

Standard & Poor’s believes that such payments will be made during such grace period. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of a similar action if payments on an obligation are jeopardized.

The ratings from ‘AA’ to ‘CCC’ may be modified by the addition of a plus (+) or minus (-) sign to show relative standing within the major rating categories.

Active Qualifiers (currently applied and/or outstanding)

Provisional ratings: The letters ‘pr’ indicate that the rating is provisional. A provisional rating assumes the successful completion of the project financed by the debt being rated and indicates that payment of debt service requirements is largely or entirely dependent upon the successful, timely completion of the project. This rating, however, while addressing credit quality subsequent to completion of the project, makes no comment on the likelihood of or the risk of default upon failure of such completion. The investor should exercise his own judgment with respect to such likelihood and risk.

i: This subscript is used for issues in which the credit factors, terms, or both, that determine the likelihood of receipt of payment of interest are different from the credit factors, terms or both that determine the likelihood of receipt of principal on the obligation. The ‘i’ subscript indicates that the rating addresses the interest portion of the obligation only. The ‘i’ subscript will always be used in conjunction with the “p”; subscript, which addresses likelihood of receipt of principal. For example, a rated obligation could be assigned ratings of “AAAp NRi” indicating that the principal portion is rated “AAA” and the interest portion of the obligation is not rated.

L: Ratings qualified with ‘L’ apply only to amounts invested up to federal deposit insurance limits.

p: This subscript is used for issues in which the credit factors, the terms, or both, that determine the likelihood of receipt of payment of principal are different from the credit factors, terms or both that determine the likelihood of receipt of interest on the obligation. The ‘p’ subscript indicates that the rating addresses the principal portion of the obligation only. The ‘p’ subscript will always be used in conjunction with the ‘i’ subscript, which addresses likelihood of receipt of interest. For example, a rated obligation could be assigned ratings of “AAAp NRi” indicating that the principal portion is rated “AAA” and the interest portion of the obligation is not rated.

pi: Ratings with a ‘pi’ subscript are based on an analysis of an issuer’s published financial information, as well as additional information in the public domain. They do not, however, reflect in-depth meetings with an issuer’s management and are therefore based on less comprehensive information than ratings without a ‘pi’ subscript. Ratings with a ‘pi’ subscript are reviewed annually based on a new year’s financial statements, but may be reviewed on an interim basis if a major event occurs that may affect the issuer’s credit quality.

Preliminary: Preliminary ratings are assigned to issues, including financial programs, in the following circumstances. Preliminary ratings may be assigned to obligations, most commonly structured and project finance issues, pending receipt of final documentation and legal opinions. Assignment of a final rating is conditional on the receipt and approval by Standard & Poor’s of appropriate documentation. Changes in the information provided to Standard & Poor’s could result in the assignment of a different rating. In addition, Standard & Poor’s reserves the right not to issue a final rating. Preliminary ratings are assigned to Rule 415 Shelf Registrations. As specific issues, with defined terms, are offered from the master registration, a final rating may be assigned to them in accordance with Standard & Poor’s policies. The final rating may differ from the preliminary rating.

t: This symbol indicates termination structures that are designed to honor their contracts to full maturity or, should certain events occur, to terminate and cash settle all their contracts before their final maturity date.

Unsolicited: Unsolicited ratings are those credit ratings assigned at the initiative of Standard & Poor’s and not at the request of the issuer or its agents.

Prospectus A-4

NR: This indicates that no rating has been requested, that there is insufficient information on which to base a rating, or that Standard & Poor’s does not rate a particular obligation as a matter of policy.

Debt obligations of issuers outside the United States and its territories are rated on the same basis as domestic corporate and municipal issues. The ratings measure the creditworthiness of the obligor but do not take into account currency exchange and related uncertainties.

Inactive Qualifiers (no longer applied or outstanding)

*: This symbol indicated continuance of the ratings is contingent upon Standard & Poor’s receipt of an executed copy of the escrow agreement or closing documentation confirming investments and cash flows. Discontinued use in August 1998.

c: This qualifier was used to provide additional information to investors that the bank may terminate its obligation to purchase tendered bonds if the long-term credit rating of the issuer is below an investment-grade level and/or the issuer’s bonds are deemed taxable. Discontinued use in January 2001.

q: A ‘q’ subscript indicates that the rating is based solely on quantitative analysis of publicly available information. Discontinued use in April 2001.

r: The ‘r’ modifier was assigned to securities containing extraordinary risks, particularly market risks, that are not covered in the credit rating. The absence of an ‘r’ modifier should not be taken as an indication that an obligation will not exhibit extraordinary non-credit related risks. Standard & Poor’s discontinued the use of the ‘r’ modifier for most obligations in June 2000 and for the balance of obligations (mainly structured finance transactions) in November 2002.

Local Currency and Foreign Currency Risks: Country risk considerations are a standard part of Standard & Poor’s analysis for credit ratings on any issuer or issue. Currency of repayment is a key factor in this analysis. An obligor’s capacity to repay foreign currency obligations may be lower than its capacity to repay obligations in its local currency due to the sovereign government’s own relatively lower capacity to repay external versus domestic debt. These sovereign risk considerations are incorporated in the debt ratings assigned to specific issues. Foreign currency issuer ratings are also distinguished from local currency issuer ratings to identify those instances where sovereign risks make them different for the same issuer.

Short Term Issue Credit Ratings

Short-term ratings are generally assigned to those obligations considered short-term in the relevant market. In the U.S., for example, that means obligations with an original maturity of no more than 365 days—including commercial paper. Short-term ratings are also used to indicate the creditworthiness of an obligor with respect to put features on long-term obligations. The result is a dual rating, in which the short-term rating addresses the put feature, in addition to the usual long-term rating. Medium-term notes are assigned long-term ratings.

A-1: A short-term obligation rated ‘A-1’ is rated in the highest category by Standard & Poor’s. The obligor’s capacity to meet its financial commitment on the obligation is strong. Within this category, certain obligations are designated with a plus sign (+). This indicates that the obligor’s capacity to meet its financial commitment on these obligations is extremely strong.

A-2: A short-term obligation rated ‘A-2’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher rating categories. However, the obligor’s capacity to meet its financial commitment on the obligation is satisfactory.

A-3: A short-term obligation rated ‘A-3’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.

A-5 PIMCO Funds

B: A short-term obligation rated ‘B’ is regarded as having significant speculative characteristics. Ratings of ‘B-1’, ‘B-2’, and ‘B-3’ may be assigned to indicate finer distinctions within the ‘B’ category. The obligor currently has the capacity to meet its financial commitment on the obligation; however, it faces major ongoing uncertainties which could lead to the obligor’s inadequate capacity to meet its financial commitment on the obligation.

B-1: A short-term obligation rated ‘B-1’ is regarded as having significant speculative characteristics, but the obligor has a relatively stronger capacity to meet its financial commitments over the short-term compared to other speculative-grade obligors.

B-2: A short-term obligation rated ‘B-2’ is regarded as having significant speculative characteristics, and the obligor has an average speculative-grade capacity to meet its financial commitments over the short-term compared to other speculative-grade obligors.

B-3: A short-term obligation rated ‘B-3’ is regarded as having significant speculative characteristics, and the obligor has a relatively weaker capacity to meet its financial commitments over the short-term compared to other speculative-grade obligors.

C: A short-term obligation rated ‘C’ is currently vulnerable to nonpayment and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation.

D: A short-term obligation rated ‘D’ is in payment default. The ‘D’ rating category is used when payments on an obligation are not made on the date due even if the applicable grace period has not expired, unless Standard & Poor’s believes that such payments will be made during such grace period. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of a similar action if payments on an obligation are jeopardized.

Dual Ratings: Standard & Poor’s assigns “dual” ratings to all debt issues that have a put option or demand feature as part of their structure. The first rating addresses the likelihood of repayment of principal and interest as due, and the second rating addresses only the demand feature. The long-term rating symbols are used for bonds to denote the long-term maturity and the short-term rating symbols for the put option (for example, ‘AAA/A-1+’). With U.S. municipal short-term demand debt, note rating symbols are used with the short-term issue credit rating symbols (for example, ‘SP-1+/A-1+’).

The issue credit rating is not a recommendation to purchase, sell, or hold a financial obligation, inasmuch as it does not comment as to market price or suitability for a particular investor. Issue credit ratings are based on current information furnished by the obligors or obtained by Standard & Poor’s from other sources it considers reliable. Standard & Poor’s does not perform an audit in connection with any credit rating and may, on occasion, rely on unaudited financial information. Credit ratings may be changed, suspended, or withdrawn as a result of changes in, or unavailability of, such information, or based on other circumstances.

Fitch, Inc. Long-Term Credit Ratings

Investment Grade

AAA: Highest credit quality. ‘AAA’ ratings denote the lowest expectation of credit risk. They are assigned only in case of exceptionally strong capacity for payment of financial commitments. This capacity is highly unlikely to be adversely affected by foreseeable events.

AA: Very high credit quality. “AA” ratings denote a very low expectation of credit risk. They indicate very strong capacity for timely payment of financial commitments. This capacity is not significantly vulnerable to foreseeable events.

Prospectus A-6

A: High credit quality. “A” ratings denote a low expectation of credit risk. The capacity for timely payment of financial commitments is considered strong. This capacity may, nevertheless, be more vulnerable to changes in circumstances or in economic conditions than is the case for higher ratings.

BBB: Good credit quality. “BBB” ratings indicate that there is currently a low expectation of credit risk. The capacity for timely payment of financial commitments is considered adequate, but adverse changes in circumstances and in economic conditions are more likely to impair this capacity. This is the lowest investment-grade category.

Speculative Grade

BB: Speculative. “BB” ratings indicate that there is a possibility of credit risk developing, particularly as the result of adverse economic change over time; however, business or financial alternatives may be available to allow financial commitments to be met. Securities rated in this category are not investment grade.

B: Highly speculative. “B” ratings indicate that significant credit risk is present, but a limited margin of safety remains. Financial commitments are currently being met; however, capacity for continued payment is contingent upon a sustained, favorable business and economic environment. For individual obligations, may indicate distressed or defaulted obligations with potential for extremely high recoveries. Such obligations would possess a Recovery Rating of ‘RR1’ (outstanding).

CCC: For issuers and performing obligations, default is a real possibility. Capacity for meeting financial commitments is solely reliant upon sustained, favorable business or economic conditions. For individual obligations, may indicate distressed or defaulted obligations with potential for average to superior levels of recovery. Differences in credit quality may be denoted by plus/minus distinctions. Such obligations typically would possess a Recovery Rating of ‘RR2’ (superior), or ‘RR3’ (good) or ‘RR4’ (average).

CC: For issuers and performing obligations, default of some kind appears probable. For individual obligations, may indicate distressed or defaulted obligations with a Recovery Rating of ‘RR4’ (average) or ‘RR5’ (below average).

C: For issuers and performing obligations, default is imminent. For individual obligations, may indicate distressed or defaulted obligations with potential for below-average to poor recoveries. Such obligations would possess a Recovery Rating of ‘RR6’ (poor).

RD: Indicates an entity that has failed to make due payments (within the applicable grace period) on some but not all material financial obligations, but continues to honor other classes of obligations.

D: Indicates an entity or sovereign that has defaulted on all of its financial obligations. Default generally is defined as one of the following:

• Failure of an obligor to make timely payment of principal and/or interest under the contractual terms of any financial obligation;

• The bankruptcy filings, administration, receivership, liquidation or other winding-up or cessation of business of an obligor;

• The distressed or other coercive exchange of an obligation, where creditors were offered securities with diminished structural or economic terms compared with the existing obligation.

Default ratings are not assigned prospectively; within this context, non-payment on an instrument that contains a deferral feature or grace period will not be considered a default until after the expiration of the deferral or grace period.

Issuers will be rated ‘D’ upon a default. Defaulted and distressed obligations typically are rated along the continuum of ‘C’ to ‘B’ ratings categories, depending upon their recovery prospects and other relevant

A-7 PIMCO Funds

characteristics. Additionally, in structured finance transactions, where analysis indicates that an instrument is irrevocably impaired such that it is not expected to meet pay interest and/or principal in full in accordance with the terms of the obligation’s documentation during the life of the transaction, but where no payment default in accordance with the terms of the documentation is imminent, the obligation may be rated in the ‘B’ or ‘CCC-C’ categories.

Default is determined by reference to the terms of the obligations’ documentation. Fitch will assign default ratings where it has reasonably determined that payment has not been made on a material obligation in accordance with the requirements of the obligation’s documentation, or where it believes that default ratings consistent with Fitch’s published definition of default are the most appropriate ratings to assign.

Recovery Ratings

Fitch Ratings’ assigns Recovery Ratings to securities and issues. These currently are published for most individual obligations of issuers with IDRs in the ‘B’ rating category and below and to structured finance securities that become distressed or have defaulted and are rated in the ‘B’ rating category and below. New issue structured finance securities typically are not assigned a Recovery Rating.

Recoveries gain in importance at lower rating levels because the likelihood of default in the near to medium term is often quite high and differences in recovery values have a more meaningful impact on loss expectations. Among the factors that affect recovery rates for an entity’s security are the collateral, the seniority relative to other obligations in the capital structure, and the company’s expected value in distress. For structured finance securities, the combination of tranche size, relative seniority, and structural features influence recovery values.

The Recovery Scale is based upon the expected relative recovery characteristics of an obligation upon the curing of a default, emergence from insolvency or following a liquidation or termination of the obligor or its associated collateral. As such, it is an ordinal scale and does not attempt to precisely predict a given level of recovery.

Recovery Ratings Scale

RR1: Outstanding recovery prospects given default.

RR2: Superior recovery prospects given default.

RR3: Good recovery prospects given default.

RR4: Average recovery prospects given default.

RR5: Below average recovery prospects given default.

RR6: Poor recovery prospects given default.

While recovery ratings are in relative terms, Fitch does employ recovery bands in its ratings approach.

RR1 rated securities have characteristics in line with securities historically recovering 91%-100% of current principal and related interest.

RR2 rated securities have characteristics in line with securities historically recovering 71%-90% of current principal and related interest.

RR3 rated securities have characteristics in line with securities historically recovering 51%-70% of principal and related interest.

RR4 rated securities have characteristics in line with securities historically recovering 31%-50% of current principal and related interest.

Prospectus A-8

RR5 rated securities have characteristics in line with securities historically recovering 11%-30% of current principal and related interest.

RR6 rated securities have characteristics in line with securities historically recovering 0%-10% of current principal and related interest.

Short-Term Credit Ratings

A Short-term rating has a time horizon of less than 13 months for most obligations, or up to three years for US public finance, in line with industry standards, to reflect unique risk characteristics of bond, tax, and revenue anticipation notes that are commonly issued with terms up to three years. Short-term ratings thus place greater emphasis on the liquidity necessary to meet financial commitments in a timely manner.

F1: Highest credit quality. Indicates the strongest capacity for timely payment of financial commitments; may have an added “+” to denote any exceptionally strong credit feature.

F2: Good credit quality. A satisfactory capacity for timely payment of financial commitments, but the margin of safety is not as great as in the case of the higher ratings.

F3: Fair credit quality. The capacity for timely payment of financial commitments is adequate; however, near-term adverse changes could result in a reduction to non-investment grade.

B: Speculative. Minimal capacity for timely payment of financial commitments, plus vulnerability to near-term adverse changes in financial and economic conditions.

C: High default risk. Default is a real possibility. Capacity for meeting financial commitments is solely reliant upon a sustained, favorable business and economic environment.

D: Default. Indicates an entity or sovereign that has defaulted on all of its financial obligations.

“+” or “-” may be appended to a rating to denote relative status within major rating categories. Such suffixes are not added to the “AAA” long-term rating category, to categories below “CCC,” or to short-term ratings other than “F1.” (The +/- modifiers are only used to denote issues within the CCC category, whereas issuers are only rated CCC without the use of modifiers.)

“NR” indicates that Fitch does not publicly rate the issuer or issue in question.

“WD” indicates that the rating has been withdrawn and is no longer maintained by Fitch.

Rating Watch: Ratings are placed on Rating Watch to notify investors that there is a reasonable probability of a rating change and the likely direction of such change. These are designated as “Positive”, indicating a potential upgrade, “Negative,” for a potential downgrade, or “Evolving,” if ratings may be raised, lowered or maintained. Rating Watch is typically resolved over a relatively short period.

A Rating Outlook indicates the direction a rating is likely to move over a one to two year period. Outlooks may be positive, stable, or negative. A positive or negative Rating Outlook does not imply a rating change is inevitable. Similarly, companies whose outlooks are “stable” could be upgraded or downgraded before an outlook moves to positive or negative if circumstances warrant such an action. Occasionally, Fitch may be unable to identify the fundamental trend. In these cases, the Rating Outlook may be described as evolving.

A-9 PIMCO Funds

PIMCO Funds INVESTMENT ADVISER AND ADMINISTRATOR

PIMCO, 840 Newport Center Drive, Newport Beach, CA 92660

DISTRIBUTOR

Allianz Global Investors Distributors LLC, 1345 Avenue of the Americas, New York,     NY 10105-4800

CUSTODIAN

State Street Bank & Trust Co., 801 Pennsylvania, Kansas City, MO 64105

TRANSFER AGENT

Boston Financial Data Services - Midwest, 330 W. 9th Street, Kansas City, MO 64105

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

PricewaterhouseCoopers LLP, 1100 Walnut Street, Suite 1300, Kansas City, MO 64106-2197

LEGAL COUNSEL

Dechert LLP, 1775 I Street N.W., Washington, D.C. 20006

The Trust’s Statement of Additional Information (“SAI”) includes additional information about the Fund. The SAI is incorporated by reference into this Prospectus, which means it is part of this Prospectus for legal purposes. The Fund’s annual report, once it is available, will discuss the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal year.

You may get free copies of the SAI, the Fund’s annual or semi-annual report (once available), request other information about the Fund, or make shareholder inquiries by calling the Trust at 1-800-927-4648 or PIMCO Infolink Audio Response Network at 1-800-987-4626, or by writing to:

PIMCO Funds

840 Newport Center Drive

Newport Beach, CA 92660

You may review and copy information about the Trust, including its SAI, at the Securities and Exchange Commission’s public reference room in Washington, D.C. You may call the Commission at 1-202-551-8090 for information about the operation of the public reference room. You may also access reports and other information about the Trust on the EDGAR Database on the Commission’s Web site at www.sec.gov. You may get copies of this information, with payment of a duplication fee, by writing the Public Reference Section of the Commission, Washington, D.C. 20549-0102, or by e-mailing your request to publicinfo@sec.gov.

You can also visit our Web site at www.pimco.com for additional information about the Fund, including the SAI and the annual and semi-annual reports, which are available for download free of charge.

Reference the Trust’s Investment Company Act file number in your correspondence.

Investment Company Act File No. 811-05028

PIMCO Funds

840 Newport Center Drive

Newport Beach, CA 92660